Launching game crashes without info

I just tried another test packaging of our current project and when the launching process starts the game it just crashes without any info. All it says is “Fatal error!” without any call stack info. Here is the log file of the staged build executable.
Its pretty hard to find the cause of this error since there isn’t any information in the log. Also starting as “standalone game” crashes without any information but “You do not have any debugging symbols required to display the callstack for this crash.”. Playing in editor works fine.
I read about a similar problem here Can't Launch Game for Windows, PIE is ok - Programming & Scripting - Unreal Engine Forums but I don’t use any custom xml file or custom folder.

//Edit: Ok, the callstack somehow reappeared. I can see now this error:

MachineId:3F8F4932429CF8C9B7B82EAFE18495B5
EpicAccountId:ecd415371e454ee0b59755727916a58a

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

UE4Editor_Engine!UEngine::GetGameUserSettings() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\unrealengine.cpp:10723]
UE4Editor_Engine!USoundCue::PostLoad() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\soundcue.cpp:108]
UE4Editor_CoreUObject!UObject::ConditionalPostLoad() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\obj.cpp:723]
UE4Editor_CoreUObject!EndLoad() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1285]

I found the issue. It was caused by my sound cue classes. I used the node “Quality Level” there with 3 different levels I defined in project settings. Removing this nodes in all sound cues solved the issue. But since I actually wanted to control the sound quality this isn’t a solution. Also the Game User Settings aren’t saved anymore, the GameUserSettings.ini just is empty after the start. May it be a bug caused by the GameUserSettings system?