plyer.filechooser.save_file doesn't work on macOS X Catalina

[Python3-8]

plyer.filechooser.save_file not working

Here's my code:

>>> from plyer import filechooser
>>> filechooser.save_file()

filechooser.choose_dir() and filechooser.open_file() work fine, but filechooser.save_file() throws an error.

Here's the error:

2020-08-12 18:27:32.088 Python[64278:918233] *** Assertion failure in +[NSServiceViewController currentAppIsViewService], /AppleInternal/BuildRoot/Library/Caches/com.apple.xbs/Sources/ViewBridge/ViewBridge-464.1/NSViewService.m:140
2020-08-12 18:27:32.135 Python[64278:918233] *** Assertion failure in +[NSServiceViewController currentAppIsViewService], /AppleInternal/BuildRoot/Library/Caches/com.apple.xbs/Sources/ViewBridge/ViewBridge-464.1/NSViewService.m:140
2020-08-12 18:27:32.737 Python[64278:918666] +[NSXPCSharedListener endpointForReply:withListenerName:]: an error occurred while attempting to obtain endpoint for listener 'com.apple.view-bridge': Connection interrupted
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/plyer/facades/filechooser.py", line 57, in save_file
    return self._file_selection_dialog(mode="save", *args, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/plyer/platforms/macosx/filechooser.py", line 119, in _file_selection_dialog
    return MacFileChooser(**kwargs).run()
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/plyer/platforms/macosx/filechooser.py", line 63, in run
    panel.setCanCreateDirectories_(True)
AttributeError: 'NoneType' object has no attribute 'setCanCreateDirectories_'

Then a while later there's this dialog saying 'Python quit unexpectedly.'

Can someone please tell me what's wrong?

[ElliotGarbus]

I am experiencing a similar issue. My app works correctly on MacOS Mojave.

Here is the error when attempting to save on Catalina:

2020-10-11 17:56:12.400 python[3204:53237] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '[NSOpenPanel setCanChooseDirectories:]: unrecognized (NSOpenPanel) selector sent to instance 0x7fc241f951d0.  This sandboxed application's NSSavePanel class object only responds to NSSavePanel APIs!  Please use the interface as described in NSSavePanel.h.'
*** First throw call stack:
(
        0   CoreFoundation                      0x00007fff3750bb57 __exceptionPreprocess + 250
        1   libobjc.A.dylib                     0x00007fff701be5bf objc_exception_throw + 48
        2   CoreFoundation                      0x00007fff3750b9b5 +[NSException raise:format:] + 189
        3   AppKit                              0x00007fff350f9e16 -[NSSavePanel setCanChooseDirectories:] + 164
        4   libffi.dylib                        0x00007fff6f108905 ffi_call_unix64 + 85
        5   ???                                 0x00007fc23faf0800 0x0 + 140472268818432
)
libc++abi.dylib: terminating with uncaught exception of type NSException
Abort trap: 6

Here is the call to save:

            filechooser.save_file(path=self.path,
                                  title='Save the Patch',
                                  on_selection=self._save_selection)

[Python3-8]

I have Mojave on another partition of my HDD. Maybe I could get it to work on it.