User comments look like its an issue with committing to GIT in editor:
No known steps to reproduce
Users are hitting this when committing to Git
I tried making a git workspace and committing a new actor, didn't hit a crash.
Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\Build\++UE4+Release-4.19+Compile\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 610] Array index out of bounds: 0 from an array of size 0 UE4Editor_GitSourceControl!FGitCheckInWorker::Execute() [gitsourcecontroloperations.cpp:100] UE4Editor_GitSourceControl!FGitSourceControlCommand::DoThreadedWork() [gitsourcecontrolcommand.cpp:39] UE4Editor_Core!FQueuedThread::Run() [threadingbase.cpp:455] UE4Editor_Core!FRunnableThreadWin::Run() [windowsrunnablethread.cpp:76]
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-56232 in the post.