unity sport engine – iOS Firebase Crashlytics UnityFramework possibly Textual content To Speech associated

I preserve getting crashes in Firebase – AudioOut.cpp line XXX wordpos_thread(void*)
Once I view the threads I can discover the thread
com.google.firebase.crashlytics.MachExceptionServer
and the thread earlier than that

          AXSpeech
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  Basis                     0xc7e4c -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 212
8  TextToSpeech                   0x27718 TTSCFAttributedStringCreateStringByBracketingAttributeWithString + 776
9  Basis                     0xde718 __NSThread__start__ + 732
10 libsystem_pthread.dylib        0x606c _pthread_start + 136
11 libsystem_pthread.dylib        0x10d8 thread_start + 8

So I believe the crash is going on when some invalid textual content is being despatched to be learn. However I don’t know easy methods to discover or repair this subject?
And I am unable to reproduce it

Any concepts can be very appreciated

Thanks

I’ve tried looking via the stack hint to search for something referring to my code.
Have discovered nothing