_Py_FatalErrorFunc not found

[Klaus Dittrich]

I need some help.

hplip as of late complains :

File "/usr/bin/hp-scan", line 40, in <module>
     import scanext
ImportError: /usr/lib/python3.9/site-packages/scanext.so: undefined 
symbol: _Py_FatalErrorFunc

Which module defines this _Py_FatalErrorFunc?

Or has the name of this function changed in python-3.9.1?
If yes what is its name now?

hplip version is the latest, hplip-3.20.11, but they have not taken 
notice of the problem as far as i know.

Any help is much appreciated
--
Klaus