!Python3 fatal error

Python has stopped working on my ARMX6.
If I double click on !Python3 it starts a python shell and stops with:

  Fatal Python error: init_import_size: Failed to import the site module
  Python runtime state: initialized

  File "SCSI::SSD.$.Apps.Development.!Python3.python38.lib.riscospath", 
  line 574, in canonicalise
  swi.swi('OS_FSControl','isbiii',37,path,buffer,0,0,256*4)
  swi.error: Filing system SCSI: must be given a filename

Can anyone suggest what is the likely cause?
There is the nuclear option of PackMan uninstall/reinstall but it would be nice to know why it is broken.

John

The usual reason for “Filing system SCSI: must be given a filename” is that a null string has been supplied instead of a pathname.

It might be worth checking what system variables Python is using, to see if any of them are not as expected following the upgrade to 5.29.

The usual reason for “Filing system SCSI: must be given a filename” is that a null string has been supplied instead of a pathname.

Thanks for the suggestion it was very helpful. I put some debug in risospath and found that PythonUser$Dir was null which prompted a memory of moving !PythonUser out of PreDesk as part of the install of 5.29.
All is well and Python works again.