Unreal Engine Fails to Launch/Build Executable

Hello,
I have a problem with my application. I am able to build/compile and rebuild the entire project. I am also able to launch the game outside of unreal with no issues. But when I click to launch it within the Unreal engine I get multiple issues when it’s building the executable. I appear to have multiple LNK errors, specifically it’s LNK 2001 and LNK2019. To try and fix it I have rebuilt it, merged it with an older working version (caused it to not work again), ran debugger to find missing dll files which there were a couple that got fixed. Thank you for any help or insight! The log is below -

LogPlayLevel: Using ‘git status’ to determine working set for adaptive non-unity build.
LogPlayLevel: Using Visual Studio 2017 14.15.26726 toolchain (C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.15.26726) and Windows 10.0.17134.0 SDK (C:\Program Files (x86)\Windows Kits\10).
LogPlayLevel: Building 1 action with 8 processes…
LogPlayLevel: [1/1] BuildingEscape.exe
LogPlayLevel: Creating library C:\Users\Documents\repos\BuildingEscape_01\BuildingEscape\Binaries\Win64\BuildingEscape.lib and object C:\Users\Documents\repos\BuildingEscape_01\BuildingEscape\Binaries\Win64\BuildingEscape.exp
LogPlayLevel: Module.Launch.cpp.obj : error LNK2019: unresolved external symbol “bool GIsGameAgnosticExe” (?GIsGameAgnosticExe@@3_NA) referenced in function “void __cdecl LaunchFixGameNameCase(void)” (?LaunchFixGameNameCase@@YAXXZ)
LogPlayLevel: Module.Core.5_of_10.cpp.obj : error LNK2001: unresolved external symbol “bool GIsGameAgnosticExe” (?GIsGameAgnosticExe@@3_NA)
LogPlayLevel: Module.BuildPatchServices.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.PakFile.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.NetworkFile.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.AutomationWorker.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.AutomationController.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.Engine.16_of_40.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.Engine.19_of_40.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.Engine.24_of_40.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.Engine.37_of_40.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.SandboxFile.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.ShaderCore.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.D3D11RHI.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.HTTP.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.Core.7_of_10.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.Core.9_of_10.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.ApplicationCore.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.CoreUObject.1_of_6.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.Launch.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.Core.2_of_10.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.Core.5_of_10.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.Core.6_of_10.cpp.obj : error LNK2001: unresolved external symbol “wchar_t * GInternalProjectName” (?GInternalProjectName@@3PA_WA)
LogPlayLevel: Module.Core.2_of_10.cpp.obj : error LNK2019: unresolved external symbol “wchar_t const * const GForeignEngineDir” (?GForeignEngineDir@@3PEB_WEB) referenced in function “public: static wchar_t const * __cdecl FGenericPlatformMisc::EngineDir(void)” (?EngineDir@FGenericPlatformMisc@@SAPEB_WXZ)
LogPlayLevel: Module.Core.5_of_10.cpp.obj : error LNK2019: unresolved external symbol “bool const GIsDebugGame” (?GIsDebugGame@@3_NB) referenced in function “public: static enum EBuildConfigurations::Type __cdecl FApp::GetBuildConfiguration(void)” (?GetBuildConfiguration@FApp@@SA?AW4Type@EBuildConfigurations@@XZ)
LogPlayLevel: C:\Users\Documents\repos\BuildingEscape_01\BuildingEscape\Binaries\Win64\BuildingEscape.exe : fatal error LNK1120: 4 unresolved externals
LogPlayLevel: ERROR: UBT ERROR: Failed to produce item: C:\Users\Documents\repos\BuildingEscape_01\BuildingEscape\Binaries\Win64\BuildingEscape.exe
LogPlayLevel: (see C:\Users\AppData\Roaming\Unreal Engine\AutomationTool\Logs\C+Program+Files+Epic+Games+UE_4.20\UBT-BuildingEscape-Win64-Development_2.txt for full exception trace)
LogPlayLevel: Total build time: 12.97 seconds (Parallel executor: 0.00 seconds)
LogPlayLevel: Took 13.2825841s to run UnrealBuildTool.exe, ExitCode=5
LogPlayLevel: ERROR: UnrealBuildTool failed. See log for more details. (C:\Users\AppData\Roaming\Unreal Engine\AutomationTool\Logs\C+Program+Files+Epic+Games+UE_4.20\UBT-BuildingEscape-Win64-Development_2.txt)
LogPlayLevel: (see C:\Users\AppData\Roaming\Unreal Engine\AutomationTool\Logs\C+Program+Files+Epic+Games+UE_4.20\Log.txt for full exception trace)
LogPlayLevel: AutomationTool exiting with ExitCode=5 (5)
LogPlayLevel: Completed Launch On Stage: Build Task, Time: 44.413977
LogPlayLevel: BUILD FAILED
PackagingResults: Error: Launch failed! Unknown Error

Did you find the problem?
I have the same issue, the engine doesn’t seem to find the “Core” module, altough it’s there in the .cs …

Cooking error : cannot link the “Core” module - Development / Programming & Scripting - Epic Developer Community Forums (unrealengine.com)
I have same issue. How did you fix it?

Also eventually figured it out myself.
Just deleted Source folder in project, just had empty c++ class created (that was the packaging issue) and all the safe to delete folders from this list: