4.12.5 crashes when I hit play

I wrote some new code last night and compiled it, but when I hit play in the editor, it crashes the engine. I tried validating everything already and that didn’t help it.

This is the crash report I am getting:

MachineId:
EpicAccountId:

SEGV_MAPERR at 0x3

FGenericPlatformMisc::RaiseException(unsigned int) Address = 0x10524574b [/Users/build/Build/++UE4+Release-4.12+Compile/Sync/Engine/Source/Runtime/Core/Private/GenericPlatform/GenericPlatformMisc.cpp, line 293] [in UE4Editor-Core.dylib]
FOutputDeviceMacError::Serialize(wchar_t const*, ELogVerbosity::Type, FName const&) Address = 0x1053e74e6 [/Users/build/Build/++UE4+Release-4.12+Compile/Sync/Engine/Source/Runtime/Core/Private/Mac/MacPlatformOutputDevices.cpp, line 93] [in UE4Editor-Core.dylib]
FOutputDevice::Logf(wchar_t const*, …) Address = 0x10549ef27 [/Users/build/Build/++UE4+Release-4.12+Compile/Sync/Engine/Source/Runtime/Core/Private/Misc/OutputDevice.cpp, line 154] [in UE4Editor-Core.dylib]
FDebug::AssertFailed(char const*, char const*, int, wchar_t const*, …) Address = 0x10549a4c4 [Runtime/Core/Public/Containers/ContainerAllocationPolicies.h, line 484] [in UE4Editor-Core.dylib]
UObject::CreateDefaultSubobject(FName, UClass*, UClass*, bool, bool, bool) Address = 0x105f3dd49 [/Users/build/Build/++UE4+Release-4.12+Compile/Sync/Engine/Source/Runtime/CoreUObject/Private/UObject/Obj.cpp, line 85] [in UE4Editor-CoreUObject.dylib]
AProjectile::BeginPlay() Address = 0x1612674e7 [/Users//04_BattleTanks/BattleTanks/Source/BattleTanks/Projectile.cpp, line 20] [in UE4Editor-BattleTanks-9152.dylib]
AWorldSettings::NotifyBeginPlay() Address = 0x10855565e [/Users/build/Build/++UE4+Release-4.12+Compile/Sync/Engine/Source/Runtime/Engine/Private/WorldSettings.cpp, line 164] [in UE4Editor-Engine.dylib]
AGameMode::HandleMatchHasStarted() Address = 0x1075b0782 [/Users/build/Build/++UE4+Release-4.12+Compile/Sync/Engine/Source/Runtime/Engine/Private/GameMode.cpp, line 623] [in UE4Editor-Engine.dylib]
AGameMode::SetMatchState(FName) Address = 0x1075b0efa [/Users/build/Build/++UE4+Release-4.12+Compile/Sync/Engine/Source/Runtime/Engine/Private/GameMode.cpp, line 733] [in UE4Editor-Engine.dylib]
UWorld::BeginPlay() Address = 0x10853625e [/Users/build/Build/++UE4+Release-4.12+Compile/Sync/Engine/Source/Runtime/Engine/Private/World.cpp, line 3218] [in UE4Editor-Engine.dylib]
UGameInstance::StartPIEGameInstance(ULocalPlayer*, bool, bool, bool) Address = 0x1075a8b4c [/Users/build/Build/++UE4+Release-4.12+Compile/Sync/Engine/Source/Runtime/Engine/Private/GameInstance.cpp, line 293] [in UE4Editor-Engine.dylib]
UEditorEngine::CreatePIEGameInstance(int, bool, bool, bool, bool, float) Address = 0x10e032caa (filename not found) [in UE4Editor-UnrealEd.dylib]
UEditorEngine::PlayInEditor(UWorld*, bool) Address = 0x10e026bf4 (filename not found) [in UE4Editor-UnrealEd.dylib]
UEditorEngine::StartQueuedPlayMapRequest() Address = 0x10e0131d4 (filename not found) [in UE4Editor-UnrealEd.dylib]
UEditorEngine::Tick(float, bool) Address = 0x10d74abf5 (filename not found) [in UE4Editor-UnrealEd.dylib]
UUnrealEdEngine::Tick(float, bool) Address = 0x10e544787 (filename not found) [in UE4Editor-UnrealEd.dylib]
FEngineLoop::Tick() Address = 0x1051762b4 (filename not found) [in UE4Editor]
GuardedMain(wchar_t const*) Address = 0x10517e4ff (filename not found) [in UE4Editor]
-[UE4AppDelegate runGameThread:] Address = 0x10518eedc (filename not found) [in UE4Editor]
-[FCocoaGameThread main] Address = 0x1053b5776 [/Users/build/Build/++UE4+Release-4.12+Compile/Sync/Engine/Source/Runtime/Core/Private/Mac/CocoaThread.cpp, line 368] [in UE4Editor-Core.dylib]
Unknown() Address = 0x7fff94468e64 (filename not found) [in Foundation]
_pthread_body Address = 0x7fff9267a99d (filename not found) [in libsystem_pthread.dylib]
_pthread_body Address = 0x7fff9267a91a (filename not found) [in libsystem_pthread.dylib]
thread_start Address = 0x7fff92678351 (filename not found) [in libsystem_pthread.dylib]

Figured it out, put the ProjectileMovement in the wrong tick function! Now it works!