Unresolved external symbol

Hello everyone. I was doing some work on my game and whenever I try to compile, I get 92 errors all saying, unresolved external symbol “public: static class FCompressedBuffer const FCompressedBuffer::Null” (?Null@FCompressedBuffer@@2V1@B) AstralQuest. This seems to happen for every file related to the player. As such I will include the player file in case I missed something. Other than that I am lost as to what the cause could be. Thank you in advance for any help.
AstralQuestCharacter.cpp (13.5 KB)
AstralQuestCharacter.h (5.2 KB)

I think your actor class needs to have YOURPROJECT_API next to it:

UCLASS(config=Game)
class ASTRALQUESTPROJECT_API AAstralQuestCharacter : public ACharacter
{

or whatever your module is called.

You should use the generate C++ class feature.

This didn’t seem to do anything and I looked at the list of errors again and it does include the player class. Before the errors showed up I was changing my enemy class so I will include that
Enemy.cpp (1.5 KB)
Enemy.h (920 Bytes)

Did you add HeadMountedDisplay module to your ProjectName.build.cs file?
And any other ‘not common’ modules that you may be using?

No I have not added any modules to the main display that I know of. My build.cs file looks like this

using UnrealBuildTool;

public class AstralQuest : ModuleRules
{
	public AstralQuest(ReadOnlyTargetRules Target) : base(Target)
	{
		PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;

		PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "HeadMountedDisplay" });
	}
}

Could you post the entire error log?
The HeadMountedDisplay is already added in your .build.cs file.

Severity Code Description Project File Line Suppression State
Error MSB3073 The command C:\Program Files\Epic Games\UE_5.0\Engine\Build\BatchFiles\Build.bat AstralQuestEditor Win64 Development -Project=C:\Users\danie\Documents\Unreal Projects\AstralQuest\AstralQuest.uproject -WaitMutex -FromMsBuild exited with code 6. AstralQuest C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160\Microsoft.MakeFile.Targets 45
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Storytriggerbase.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\MainMenu.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\MainUserDisplay.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\MyUserWidget.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Powersource.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\InteractionComponent.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\InteractionWidget.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Inventory.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Item.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseWeapon.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BasicRecipe.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\CraftingItem.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Enemy.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseNPC.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BasePants.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseSE.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Baseshirt.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestGameMode.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestPlayerController.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseBoss.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseMiner.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Storytriggerbase.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuest.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuest.init.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestCharacter.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\MainMenu.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\MainUserDisplay.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseNPC.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseSE.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestCharacter.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestGameMode.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestPlayerController.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\InteractionWidget.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Powersource.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseWeapon.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Inventory.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Item.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Enemy.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BasePants.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Baseshirt.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseMiner.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\InteractionComponent.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BasicRecipe.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\CraftingItem.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompositeBuffer const FCompositeBuffer::Null (?Null@FCompositeBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseBoss.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Storytriggerbase.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\MainMenu.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\MainUserDisplay.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\MyUserWidget.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Powersource.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\InteractionComponent.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\InteractionWidget.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Inventory.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Item.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseWeapon.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BasicRecipe.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\CraftingItem.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Enemy.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseNPC.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BasePants.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseSE.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Baseshirt.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestGameMode.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestPlayerController.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseBoss.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseMiner.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Storytriggerbase.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuest.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuest.init.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestCharacter.gen.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\MainMenu.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\MainUserDisplay.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseNPC.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseSE.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestCharacter.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestGameMode.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\AstralQuestPlayerController.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\InteractionWidget.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Powersource.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseWeapon.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Inventory.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Item.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Enemy.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BasePants.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\Baseshirt.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseMiner.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\InteractionComponent.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BasicRecipe.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\CraftingItem.cpp.obj 1
Error LNK2001 unresolved external symbol public: static class FCompressedBuffer const FCompressedBuffer::Null (?Null@FCompressedBuffer@@2V1@B) AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Intermediate\ProjectFiles\BaseBoss.cpp.obj 1
Error LNK1120 2 unresolved externals AstralQuest C:\Users\danie\Documents\Unreal Projects\AstralQuest\Binaries\Win64\UnrealEditor-AstralQuest.dll 1

Could you close Visual Studio, try to open the project in Unreal. If it show errors could you post the Unreal’s error log? Or the errors that are shown when you try to compile from Unreal?
ProjectFolder/Saved/Logs

AstralQuest.log (34.1 KB)
Here this one was much smaller in file size than the logs from when I compile from visual studios. Hope it helps.

What I’d do:
1 - Verify Unreal installation.
2 - Delete Binaries and Intermediate folder.
3 - Try to compile again.

If it still doesn’t work it is probably some #include from some module I guess.

Note: You can post code/logs/etcs as Preformatted text in your response, it’s easier for us to see.

Thank you this worked. I think the problem came from me deleting some C++ files and not refreshing. But I am glad it is working now.

As a follow up to my question (which hasn’t been mod approved as of writing), deleting Intermediate and Binaries did work, but only after noting that Visual Studio was looking for a file within Intermediate/ProjectFiles. I placed that folder back in manually and the whole thing works again.

I’m having the exact same problem, blocking my entire project from compiling or opening in editor. Would you mind providing more detail about how exactly you fixed it?
Deleting Binaries and Intermediate folders only created more errors until I put them back, it still didn’t compile

I verified my installation of unreal engine in the epic launcher then I deleted the binaries and intermediate folders as well as the visual studio solution then I clicked on the .uprose the and selected generate visual studio project and compiled.