Editor Crash Running Frontend Session

anonymous_user_0da73ff6 · December 12, 2020, 11:14pm

I’ve discovered some very strange behavior with my Session Frontend. This is the first time I’ve ever used the session frontend in this project and one of my first times ever, but whenever I open it via Window → Developer Tools → Session Frontend my .sln reports this error as I am running the editor:

Exception thrown at 0x00000000680C4361 (dbghelp.dll) in UE4Editor-Win64-DebugGame.exe: 0xC0000005: Access violation reading location 0x0000000000000000.

I’ve tried building UnrealFrontend via my UE4 source build solution and as well as my project solution and have been able to successfully run Unreal Frontend standalone. However doing it via editor crashes.

Steps to Reproduce:

Run debugger for UE4 4.26 project via VS 2019
Open Frontend Session via Window → Developer Tools → Frontend Session
Wait a few seconds
See a breakpoint hit with exception

Top function call in the call stack is

if( SymGetSymFromAddr64( ProcessHandle, ProgramCounter, nullptr, Symbol ) )

in Engine\Source\Runtime\Core\Private\Windows\WindowsPlatformStackWalk.cpp

Followed by a bunch of other non-project calls.

I’m not sure where to find the crash dump or log files, its not in the project Saved/Crashes nor is there a crashes folder in the UE4 source build Saved directory

If this is helpful, the last thing in the output before the crash is: ‘UE4Editor-Win64-DebugGame.exe’ (Win32): Loaded ‘C:\Windows\System32\psapi.dll’.

nioannides · December 17, 2020, 1:20pm

I get the exact same crash with 4.25

RemRemRemRe · January 4, 2021, 8:57am

I encountered this exception in “FSourceCodeNavigationImpl::NavigateToFunctionSource”.

Which means every time I double clicked a blueprint node and try to find it’s definition in c plus plus, it would trigger this exception.

My solution:

Delete or rename dbghelp.dll in UnrealEngine\Engine\Binaries\ThirdParty\DbgHelp folder

anonymous_user_0d5d0b83 · January 5, 2021, 3:38pm

Hello,

We’ve made a switch to a new bug reporting method using a more structured form. Please visit the link below for more details and report the issue using the new Bug Submission Form. Feel free to continue to use this thread for community discussion around the issue.

Thanks

DaveCSumo · January 14, 2021, 7:08pm

The version of dbghelp.dll supplied with the engine is soooooooooo old it can’t handle the latest debug info output by the compiler. My Visual Studio 2019 updated yesterday to 16.8.4 and looks like it came with a new dbghelp.dll so I copied that into the engine folder and no more crashes. On mine, the new dll was in

C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\Team Tools\Performance Tools

and copied it into

Engine\Binaries\ThirdParty\DbgHelp

The one supplied with the engine was 6.11.1.404 and the latest I replaced it with was 10.0.10150.0

Burnrate · January 19, 2021, 12:47am

Did you ever figure this out? I’m still getting it in 4.26
EDIT:
Oops, I somehow missed the fix by DaveCSumo!

ArcainOne · January 19, 2021, 3:32am

Thank you DaveCSumo! This fixed my Session Frontend which was crashing in a custom 4.25 engine!

gobo_prosser · January 21, 2021, 7:01am

Thank you, this fixed my issue after updating to VS 16.8.3

DaveCSumo · January 21, 2021, 9:59am

Also make sure you copy the correct version - for us it was the one in the X64 subdirectory.

Helghast · January 25, 2021, 12:22pm

This solution has worked for me. Deleting the DLL loads the Windows one, and UE4editor opens all fine with the SessionFrontend open.
‘UE4Editor.exe’ (Win32): Loaded ‘C:\Windows\System32\dbghelp.dll’.

Xyzyx · January 26, 2021, 3:54pm

I deleted Engine/Binaries/ThirdParty/DbgHelp and now debugging works fine for me. Thanks