TypeError: 'str' object is not callable

[Luca]

calibre, version 6.19.0
ERRORE: Eccezione non gestita: <b>TypeError</b>:'str' object is not callable

calibre 6.19 Portable embedded-python: True
Windows-10-10.0.22621-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.22621')
Python 3.10.1
Windows: ('10', '10.0.22621', 'SP0', 'Multiprocessor Free')
Interface language: it
Successfully initialized third party plugins: DeACSM (0, 0, 16) && LCPL Input (0, 0, 5) && Gather KFX-ZIP (from KFX Input) (1, 51, 0) && DeDRM (10, 0, 3) && Package KFX (from KFX Input) (1, 51, 0) && KFX metadata reader (from KFX Input) (1, 51, 0) && KFX Input (1, 51, 0) && Set KFX metadata (from KFX Output) (1, 67, 0) && KFX Output (1, 67, 0) && Obok DeDRM (10, 0, 0)
Traceback (most recent call last):
  File "calibre\gui2\actions\edit_metadata.py", line 438, in edit_metadata
  File "calibre\gui2\actions\edit_metadata.py", line 461, in edit_metadata_for
  File "calibre\gui2\actions\edit_metadata.py", line 491, in do_edit_metadata
  File "calibre\gui2\metadata\single.py", line 1274, in edit_metadata
  File "calibre\gui2\metadata\single.py", line 71, in __init__
  File "calibre\gui2\metadata\single.py", line 116, in setupUi
  File "calibre\gui2\metadata\single.py", line 207, in create_basic_metadata_widgets
  File "calibre\gui2\metadata\basic_widgets.py", line 706, in __init__
  File "calibre\gui2\metadata\basic_widgets.py", line 709, in enable
  File "calibre\gui2\metadata\basic_widgets.py", line 634, in current_val
TypeError: 'str' object is not callable

[ownedbycats (ownedbycats)]

There's a hotfix version available. Re-download from website.