I have a somewhat basic streaming map setup for a game I’m working on, and I’m encountering a consistent, repeatable engine crash in 4.12.3 when unloading one of the streaming maps via Blueprint.
Specifically, the log file returns this error:
[2016.08.03-02.48.34:780][953]LogCrashTracker:
[2016.08.03-02.48.34:902][953]LogWindows: Windows GetLastError: The operation completed successfully. (0) [2016.08.03-02.48.34:903][953]LogThreadingWindows:Error: Runnable thread RenderThread 3 crashed. [2016.08.03-02.48.34:903][953]LogCrashTracker:
[2016.08.03-02.48.34:903][953]LogWindows:Error:
=== Critical error: === Assertion failed: (GIsCriticalError || !NumMarks) [File:U:\UnrealEngine-4.12\Engine\Source\Runtime\Core\Public\Misc\MemStack.h] [Line: 72]
Crash in runnable thread RenderThread 3
[2016.08.03-02.48.34:903][953]LogWindows: Windows GetLastError: The operation completed successfully. (0) [2016.08.03-02.48.34:903][953]LogWindows:Error: HandleError re-entered. [2016.08.03-02.48.34:903][953]LogWindows: FPlatformMisc::RequestExit(1)
Now, some info about the map in question:
The streaming map hierarchy looks like this:
What I’m doing is loading the Persistent map (which is empty except for a few manager actors), then I load “StartMenu”, which also loads the Main Menu widget.
When you hit “New Game” on that widget, it’s supposed to unload “StartMenu”, load the “Loading” map, and then after a small delay it would load one of the other gameplay maps.
The error occurs when the Blueprint script begins to unload the “StartMenu” map. If I skip unloading this streaming map, things seem to work just fine.
This leads me to believe it’s something specific to this map. The error in the log files is not very descriptive, so I don’t really have any ideas about where to begin.
I’ve found [this post][2] where OP had more or less the same error, but the initial problem is much different leading me to believe this Assertion failed: (GIsCriticalError || !NumMarks) error is more of a general crash when the editor just has a problem loading something from memory.
So, ok, there’s something in my map that is corrupted or bad, causing this issue.
[Next thread I come to][3] is a post where a guy is having trouble unloading a streaming map with a landscape, in Unreal 4.4. Sure enough, my “StartMenu” map has a landscape in it with a somewhat complicated material. However that post says the issue was to be fixed in UE 4.5.
Either way, I tried to make some edits where the blueprint would delete the landscape before unloading the map, but that didn’t work for me.
Any ideas?