[Bug report] UnboundLocalError: cannot access local variable 'metadata' where it is not associated with a value

[thorsby-1]

Can't save the output after successful translation:

Basic informationcalibre, version 7.7.0

calibre 7.7 embedded-python: True
Windows-10-10.0.19045-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.19045')
Python 3.11.5
Windows: ('10', '10.0.19045', 'SP0', 'Multiprocessor Free')
Interface language: de
EXE path: C:\Program Files\Calibre2\calibre.exe
Successfully initialized third party plugins: DeDRM (7, 2, 1) && Ebook Translator (2, 3, 1)
Traceback (most recent call last):
File "calibre\gui2_init_.py", line 756, in dispatch
File "calibre_plugins.ebook_translator.lib.conversion", line 269, in translate_done
UnboundLocalError: cannot access local variable 'metadata' where it is not associated with a value