Cannot run UE 5.3 Editor on MacOS Sonoma 14.3.1

DigitalGreenTea · March 29, 2024, 8:46am

Hi all,

I’ve recently upgraded to a Mac Studio with macOS Sonoma 14.3.1 and installed Xcode 15. I use the launcher version of UE5.3. I understand these versions are ahead of what the Unreal Engine documentation typically recommends, and as far as I know, downgrading isn’t an option for me on Mac?

While the build for my UE game editor completes successfully, running the editor leads to a breakpoint issue, a Main Thread Checker violation for UI-related methods called on a background thread. Here are the specific errors:

“Thread 5: EXC_BREAKPOINT (code=1, subcode=0x10257565c)”
"Main Thread Checker: UI API called on a background thread: -[NSApplication isActive] …
“Unable to open mach-O at path: default.metallib Error:2”
"Main Thread Checker: UI API called on a background thread: -[NSApplication keyWindow] …

(see full error logs below)

From my understanding, these messages indicate that certain UI-related methods (-[NSApplication isActive] and -[NSApplication keyWindow]) are being called on a background thread, which goes against the macOS development rules.

I’ve spent some time searching for solutions online and tinkering with settings in Xcode, but I haven’t found a solution that addresses these issues. I’m reaching out to the community in hopes that someone may have encountered similar issues or could offer guidance on how to resolve these errors. Any advice or suggestions would be greatly appreciated.

"Thread 5: EXC_BREAKPOINT (code=1, subcode=0x10257565c)"
"Main Thread Checker: UI API called on a background thread: -[NSApplication isActive]
PID: 1850, TID: 23314, Thread name: (none), Queue name: com.apple.root.default-qos.overcommit, QoS: 0
Backtrace:
4   UnrealEditor-ApplicationCore.dylib  0x0000000101712efc _ZN10FMacCursor16UpdateVisibilityEv + 48
5   UnrealEditor-ApplicationCore.dylib  0x0000000101717398 _ZN10FMacCursor7SetTypeEN12EMouseCursor4TypeE + 276
6   UnrealEditor-ApplicationCore.dylib  0x0000000101716aa8 _ZN10FMacCursorC2Ev + 1044
7   UnrealEditor-ApplicationCore.dylib  0x0000000101706d3c _ZN15FMacApplicationC2Ev + 76
8   UnrealEditor-ApplicationCore.dylib  0x00000001017182c4 _ZN27FMacPlatformApplicationMisc17CreateApplicationEv + 32
9   UnrealEditor-Slate.dylib            0x0000000103936ef8 _ZN17FSlateApplication6CreateEv + 56
10  UnrealEditor                        0x0000000100349180 _ZN11FEngineLoop23PreInitPreStartupScreenEPKDs + 21880
11  UnrealEditor                        0x000000010033efb4 _Z11GuardedMainPKDs + 236
12  UnrealEditor                        0x000000010035aaac -[UEAppDelegate runGameThread:] + 116
13  UnrealEditor-Core.dylib             0x0000000104b4148c -[FCocoaGameThread main] + 240
14  Foundation                          0x0000000188186f14 __NSThread__start__ + 716
15  libsystem_pthread.dylib             0x00000001044e9628 _pthread_start + 136
16  libsystem_pthread.dylib             0x00000001044f3ac0 thread_start + 8"

"Unable to open mach-O at path: default.metallib Error:2"

PID: 1850, TID: 23314, Thread name: (none), Queue name: com.apple.root.default-qos.overcommit, QoS: 0
Backtrace:
4   UnrealEditor-ApplicationCore.dylib  0x0000000101713054 ___ZN15FMacApplication28OnApplicationDidBecomeActiveEv_block_invoke + 72
5   UnrealEditor-Core.dylib             0x0000000104b41210 _ZN19FCocoaRunLoopSource7ProcessEPK10__CFString + 568
6   UnrealEditor-Core.dylib             0x0000000104b40fc0 -[FCocoaRunLoopSourceInfo perform] + 308
7   CoreFoundation                      0x00000001870839dc __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28
8   CoreFoundation                      0x0000000187083970 __CFRunLoopDoSource0 + 176
9   CoreFoundation                      0x00000001870836e0 __CFRunLoopDoSources0 + 244
10  CoreFoundation                      0x00000001870822d0 __CFRunLoopRun + 828
11  CoreFoundation                      0x000000018708193c CFRunLoopRunSpecific + 608
12  UnrealEditor-Core.dylib             0x0000000104b41b68 _Z23ProcessGameThreadEventsv + 56
13  UnrealEditor-ApplicationCore.dylib  0x000000010171c228 _ZN18FMacPlatformSplash13SetSplashTextEN14SplashTextType4TypeEPKDs + 484
14  UnrealEditor-UnrealEd.dylib         0x0000000110c098a4 _ZN22FFeedbackContextEditor16ProgressReportedEf5FText + 1880
15  UnrealEditor-Core.dylib             0x0000000104c28538 _ZN16FFeedbackContext8UpdateUIEv + 200
16  UnrealEditor-TargetPlatform.dylib   0x000000010cd424f4 _ZN28FTargetPlatformManagerModule26DiscoverAvailablePlatformsEv + 1916
17  UnrealEditor-TargetPlatform.dylib   0x000000010cd39d38 _ZN28FTargetPlatformManagerModule18GetTargetPlatformsEv + 40
18  UnrealEditor-TargetPlatform.dylib   0x000000010cd391d8 _ZN28FTargetPlatformManagerModule24GetActiveTargetPlatformsEv + 172
19  UnrealEditor-TargetPlatform.dylib   0x000000010cd38368 _ZN28FTargetPlatformManagerModuleC2Ev + 1388
20  UnrealEditor-TargetPlatform.dylib   0x000000010cd31da8 InitializeModule + 32
21  UnrealEditor-Core.dylib             0x0000000104cbfb24 _ZN14FModuleManager27LoadModuleWithFailureReasonE5FNameR17EModuleLoadResult16ELoadModuleFlags + 4152
22  UnrealEditor-Core.dylib             0x0000000104cbe858 _ZN14FModuleManager10LoadModuleE5FName16ELoadModuleFlags + 144
23  UnrealEditor-Core.dylib             0x0000000104c0ceb0 _Z24GetTargetPlatformManagerb + 152
24  UnrealEditor-RenderCore.dylib       0x000000010247b46c _Z15RenderUtilsInitv + 1736
25  UnrealEditor                        0x00000001003486f0 _ZN11FEngineLoop23PreInitPreStartupScreenEPKDs + 19176
26  UnrealEditor                        0x000000010033efb4 _Z11GuardedMainPKDs + 236
27  UnrealEditor                        0x000000010035aaac -[UEAppDelegate runGameThread:] + 116
28  UnrealEditor-Core.dylib             0x0000000104b4148c -[FCocoaGameThread main] + 240
29  Foundation                          0x0000000188186f14 __NSThread__start__ + 716
30  libsystem_pthread.dylib             0x00000001044e9628 _pthread_start + 136
31  libsystem_pthread.dylib             0x00000001044f3ac0 thread_start + 8"

DigitalGreenTea · March 29, 2024, 9:54am

I was able to fix the issue.

When trying to run my game’s editor I got the following error:

Assertion failed: !bInitializedSerializationHistory [File:./Runtime/RenderCore/Private/VertexFactory.cpp] [Line: 125] VF type was loaded after engine init, use ELoadingPhase::PostConfigInit on your module to cause it to load earlier.

_GLOBAL__sub_I_Module.Water.cpp Address = 0x317700ae8 (filename not found) [in UnrealEditor-Water.dylib]

I had the Water plugin enabled and used it in my cpp-classes at one point. I disabled the plugin in the midst of development and forgot to take the Water module out of the PublicDependencyModuleNames in the build.cs file.

If anyone encounters a similar issue, check if you have plugin references still in your code before disabling a plugin!