AMadLad
March 24, 2026, 7:11pm
1
Here’s what the crash log says:
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x0000000000000000
UnrealEditor_Project_2703!BlueprintFunctionScriptThing::function() [C:\Users\Admin\Documents\Unreal Projects\Project5.0\Source\Project\Private\BlueprintFunctionScriptThing.cpp:42]
I narrowed it down to the player pawn, but not sure why it has to do with it crashing
Dumple1
March 25, 2026, 11:07am
3
A M a d L a d:
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x0000000000000000
UnrealEditor_Project_2703!BlueprintFunctionScriptThing::function() [C:\Users\Admin\Documents\Unreal Projects\Project5.0\Source\Project\Private\BlueprintFunctionScriptThing.cpp:42]
I narrowed it down to the player pawn, but not sure why it has to do with it crashing
The problem is a null pointer: you are trying to access a memory pointer that has not been initialized yet, so it is nullptr.
Let’s take a look at this file.
1 Like
AMadLad
March 25, 2026, 9:00pm
4
{
UNiagaraComponent* particlesystem = UNiagaraFunctionLibrary::SpawnSystemAttached(DebrisSystem, impactobject, NAME_None,FVector::ZeroVector, FRotator::ZeroRotator, EAttachLocation::KeepRelativeOffset, true, true, ENCPoolMethod::None, true);
particlesystem->AttachToComponent(impactobject, FAttachmentTransformRules::SnapToTargetIncludingScale, NAME_None);
if (IsValid(impactobject->GetOwner()))
{
Countsie
March 25, 2026, 9:22pm
5
To prevent the crash, verify DebrisSystem and impactobject are valid before the spawnsystemattached is called… something along the lines of:
Then verify you have a valid particlesystem after you create it, in case it fails to create the system. Add some logging in there to output what you’re missing.
AMadLad
March 26, 2026, 1:13am
6
like this?
if (IsValid(DebrisSystem)||IsValid(impactobject))
{
UNiagaraComponent* particlesystem = UNiagaraFunctionLibrary::SpawnSystemAttached(DebrisSystem, impactobject, NAME_None,FVector::ZeroVector, FRotator::ZeroRotator, EAttachLocation::KeepRelativeOffset, true, true, ENCPoolMethod::None, true);
if (IsValid(DebrisSystem) || IsValid(impactobject))
{
if (IsValid(DebrisSystem) || IsValid(impactobject))
{
particlesystem->AttachToComponent(impactobject, FAttachmentTransformRules::SnapToTargetIncludingScale, NAME_None);
}
else UE_LOG(LogTemp, Log, TEXT("CrashIndicator"));
if (IsValid(impactobject->GetOwner()))
{
particlesystem->SetNiagaraVariableActor("BuildingModule", impactobject->GetOwner());
}
particlesystem->SetNiagaraVariableFloat("Scale", 1);
UNiagaraDataInterfaceArrayFunctionLibrary::SetNiagaraArrayInt32(
particlesystem,
FName("MeshIndexes"),
meshindexes
);
TArray<int32> rendereditems = UNiagaraDataInterfaceArrayFunctionLibrary::GetNiagaraArrayInt32(
particlesystem,
"MeshIndexes"
);
particlesystem->SetVisibleFlag(true);
for (int i = 0; i < rendereditems.Num() - 1;i++)
{
//UE_LOG(LogTemp, Log, TEXT("Index: %i"), rendereditems[i]);
}
impactobject->SetVisibility(false);
}
else UE_LOG(LogTemp, Log, TEXT("CrashIndicator"));
Countsie
March 26, 2026, 3:31am
7
You only need to validate them once before they are used to make sure they are pointing to an invalid object before using them. If the object is invalid, it will crash as you’ve seen, you want to catch these situations and handle them.
generally its easier and cleaner to validate inputs at the beginning of the function. If they aren’t valid, early out by 'return’ing. add a log entry in the block with the return so you know why it didn’t complete the function.
then after you create and populate the particlesystem pointer, do a:
if(!particlesystem)
{
UE_LOG(LogTemp, Log, Text("Error creating particle system, invalid"));
return;
}
AMadLad
March 26, 2026, 3:35am
8
I’ll try that tomorrow and see if it worked
AMadLad
March 26, 2026, 3:48pm
9
fixed, I tried with that code and without it and the one without it crashed and the other one didn’t, thank you
1 Like
