However, I noticed this error on the screen, though the GUI is working without any problems.
Code:
# [2020-09-26 07:48] maxg@maxg-pc-mint ~ $
calibre
Upgrading database to version 24...
Failed to parse old style options string with error: 'ascii' codec can't decode byte 0xd9 in position 1: ordinal not in range(128)
(xreader:428896): Gtk-CRITICAL **: 09:28:33.581: gtk_action_set_visible: assertion 'GTK_IS_ACTION (action)' failed
(xreader:428896): Gtk-CRITICAL **: 09:28:33.581: gtk_action_set_visible: assertion 'GTK_IS_ACTION (action)' failed