Widget crashing with *** Terminating app due to uncaught exception 'NSFileHandleOperationException', reason: '*** -[NSConcreteFileHandle fileDescriptor]: Invalid argument'

I think this could happen when you call completion 2 times.

I have got this crash too, but it happened when scroll this widget in widget install menu.
This description of crash is not informative at all! @Apple

Thanks @boerni.

In our testing, it definitely causes an exception if you call completion more than once, but it seems to be a little different - "No such file or directory" instead of "Invalid Argument".

Code Block 
* Terminating app due to uncaught exception 'NSFileHandleOperationException', reason: '* -[NSConcreteFileHandle fileDescriptor]: No such file or directory'
terminating with uncaught exception of type NSException

Having said that, I'll see if I can find any ways that ours could possibly call completion more than once and see if that helps.

Hello everyone. We have something similar, a crash in WidgetExtension. Report says:

Code Block 
Exception Type:  EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note:  EXC_CORPSE_NOTIFY
Triggered by Thread:  0
Last Exception Backtrace:
0   CoreFoundation                	0x1b00fc878 exceptionPreprocess + 220 (NSException.m:199)
1   libobjc.A.dylib               	0x1c4652c50 objc_exception_throw + 60 (objc-exception.mm:565)
2   Foundation                    	0x1b13ea7f4 _NSFileHandleRaiseOperationExceptionWhileReading + 280 (NSFileHandle.m:71)
3   Foundation                    	0x1b13ea25c _NSFileHandleRaiseOperationException + 20 (NSFileHandle.m:75)
4   Foundation                    	0x1b13a9d58 -[NSConcreteFileHandle fileDescriptor] + 56 (NSFileHandle.m:640)
5   SwiftUI                       	0x1b6bff814 FileArchiveWriter.appendBytes(_:size:) + 52 (ArchiveData.swift:160)
6   SwiftUI                       	0x1b6bffa88 FileArchiveWriter.append<A>(_:) + 200 (ArchiveData.swift:154)
7   SwiftUI                       	0x1b6bfef04 ArchiveWriter.addAttachment(data:) + 372 (ArchiveData.swift:79)
8   SwiftUI                       	0x1b6c010bc Encoder.encodeAttachedValue<A>(key:data:) + 460 (ArchiveData.swift:362)
9   SwiftUI                       	0x1b6fa07ac CodableCGImage.encode(to:) + 136 (CodableImage.swift:111)
10  SwiftUI                       	0x1b6fa0c64 protocol witness for Encodable.encode(to:) in conformance CodableCGImage + 20 (<compiler-generated>:0)
11  libswiftCore.dylib            	0x1b3ffbcd8 dispatch thunk of Encodable.encode(to:) + 28
12  libswiftFoundation.dylib      	0x1b3b94b64 PlistEncoder.box_<A>(_:) + 340 (PlistEncoder.swift:523)
13  libswiftFoundation.dylib      	0x1b3b95fb8 _PlistKeyedEncodingContainer.encode<A>(_:forKey:) + 492 (PlistEncoder.swift:508)
14  libswiftFoundation.dylib      	0x1b3b97184 protocol witness for KeyedEncodingContainerProtocol.encode<A>(_:forKey:) in conformance _PlistKeyedEncodingContainer<A> + 32 (<compiler-generated>:0)
15  libswiftCore.dylib            	0x1b3d17048 _KeyedEncodingContainerBox.encode<A, B>(_:forKey:) + 404 (Codable.swift:3732)
16  libswiftCore.dylib            	0x1b3d0b1ac KeyedEncodingContainer.encode<A>(_:forKey:) + 52 (Codable.swift:677)
17  SwiftUI                       	0x1b6a2594c GraphicsImage.encode(to:) + 392 (GraphicsImage.swift:124)
18  SwiftUI                       	0x1b6a26294 protocol witness for Encodable.encode(to:) in conformance GraphicsImage + 16 (<compiler-generated>:0)
19  libswiftCore.dylib            	0x1b3ffbcd8 dispatch thunk of Encodable.encode(to:) + 28
...

We are still investigating this crash. We definitely don't see our code at all.

Any updates on this error message? Running into the same exact error and have no clue how to resolve. I double checked that I am not calling completion multiple times.

Check you aren't calling the completion handler on a background thread. That solved my issue...