Crash __CFRunLoopServiceMachPort - 99% background

I'm having the same problem here

Did you solve it?

And are you using any Firebase service such as Analytics, Crashlytics etc?

You won’t be able to debug this based on the info from your third-party crash reporter. In fact, I’m not ever sure there’s anything to debug! The crash report says that it’s crashed here:

Crashed: com.apple.main-thread
0  libsystem_kernel.dylib 0x1808 mach_msg2_trap + 8
1  libsystem_kernel.dylib 0x5008 mach_msg2_internal + 80
2  libsystem_kernel.dylib 0x4f20 mach_msg_overwrite + 436
3  libsystem_kernel.dylib 0x4d60 mach_msg + 24
4  CoreFoundation         0x53f5c __CFRunLoopServiceMachPort + 160
5  CoreFoundation         0x53600 __CFRunLoopRun + 1208
6  CoreFoundation         0x52cd8 CFRunLoopRunSpecific + 608
7  GraphicsServices       0x11a8 GSEventRunModal + 164
8  UIKitCore              0x40a90c -[UIApplication _run] + 888
9  UIKitCore              0x4be9d0 UIApplicationMain + 340
10 UIKitCore              0x638384 keypath_get_selector_hoverStyle + 11024
11 MYAPP                  0x6a348 main + 4365591368 (YAppDelegate.swift:4365591368)
12 ???                    0x1abc85e4c (Missing)

but that makes no sense. This indicates that your main thread crashed, but the main thread is suspended in its run loop waiting for an event to arrive.

IMO you should disable this third-party crash reporter [1] and see if you get an Apple crash report. If so, please post that here, using the process described in Posting a Crash Report.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

[1] Because third-party crash reporter can, and often do, mess up the Apple crash reporter. See Implementing Your Own Crash Reporter for all the gory details here.

Thank you @DTS Engineer .

It looks Firebase is the main problem here (a lot of issues opened days ago), @iamgaspar check this https://github.com/firebase/firebase-ios-sdk/releases/tag/10.28.1. I've just found that :)