Crash in Git provider when compiling blueprint

I have this error very often when compiling blueprint in my project. It happens every 3rd or 4th time I press Compile button, so it is very annoying. Both 4.8.0 and 4.8.1 versions are affected.

Here is stack trace of the crash:

Access violation - code c0000005 (first/second chance not available)


UE4Editor_SourceControl!FSourceControlModule::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\developer\sourcecontrol\private\sourcecontrolmodule.cpp:223]
UE4Editor_UnrealEd!UEditorEngine::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\editor\unrealed\private\editorengine.cpp:1489]
UE4Editor_UnrealEd!UUnrealEdEngine::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\editor\unrealed\private\unrealedengine.cpp:366]
UE4Editor!FEngineLoop::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\runtime\launch\private\launchengineloop.cpp:2359]
UE4Editor!GuardedMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\runtime\launch\private\launch.cpp:142]
UE4Editor!GuardedMainWrapper() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]

EDIT: I found a way to reproduce it:

  1. Create a blank project.
  2. Create a git repository inside the folder of the new project.
  3. Setup connection to source control.
  4. Close editor and open it again.
  5. Create Actor blueprint.
  6. Enable “Save on Success only” compilation option inside the blueprint editor.
  7. Make some changes to Components, Event graph or anything you like and press compile.
  8. After one or two attempts it crashes.

EDIT 2: Possibly related to this bug. I get almost identical crash stack trace when try to rename a blueprint under source control through Content Browser. Looks like editor performs similar operations when renaming and saving after compilation.

Hey Druha-

Could you post the log files from the crash as well? Additionally does the crash occur if you are not connected to source control? Are you able to reproduce this crash in a new project? If it does crash in a new project is it simply by creating a blueprint and compiling multiple times? If possible please include the steps taken that caused the crash.


Hey -

I finally managed to reproduce it and added all necessary steps to the opening post.

Hello Druha,

Thank you for the thorough repro steps. I’ve reproduced the issue and entered a bug report for it in our system. For your reference, the bug number is UE-18909. Unfortunately I cannot think of a workaround to provide you with at this time. Hopefully we’ll have this issue solved as soon as possible.

Have a nice day,


I just wanted to add that I’m having the same issue, reproduced in the same way, with source control via SVN in 4.8.2.