[JimmXinu]

@kiwidude - It gave me an error on start up:

Starting up...
Generate Cover - Upgrading from schema: 1.35
Generate Cover - Upgrading to 1.41 from schema: 1.35
Traceback (most recent call last):
  File "site-packages\calibre\gui2\ui.py", line 125, in __init__
  File "site-packages\calibre\gui2\ui.py", line 139, in init_iaction
  File "site-packages\calibre\customize\__init__.py", line 543, in load_actual_plugin
  File "importlib\__init__.py", line 37, in import_module
  File "site-packages\calibre\customize\zipplugin.py", line 150, in load_module
  File "calibre_plugins.generate_cover.action", line 16, in <module>
  File "site-packages\calibre\customize\zipplugin.py", line 150, in load_module
  File "calibre_plugins.generate_cover.config", line 126, in <module>
  File "calibre_plugins.generate_cover.config", line 92, in migrate_config_if_required
  File "calibre_plugins.generate_cover.config", line 118, in migrate_config_setting
NameError: global name 'current' is not defined

Addendum: Starting calibre again doesn't throw that error.

I've attached a copy of my pre-conversion Generate Cover.json file.