EpubSplit Attribute Error

[Michael Whitmill]

Attribute Error Exception running EpubSplit. This happens "immediately" upon request. Ill upload the pop-up error message, but following are the error details:

calibre, version 7.13.0
ERROR: Unhandled exception: <b>AttributeError</b>:'NoneType' object has no attribute 'getElementsByTagName'

calibre 7.13 embedded-python: True
Windows-10-10.0.22631-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.22631')
Python 3.11.5
Windows: ('10', '10.0.22631', 'SP0', 'Multiprocessor Free')
Interface language: None
EXE path: C:\Program Files\Calibre2\calibre.exe
Successfully initialized third party plugins: Gather KFX-ZIP (from KFX Input) (2, 15, 0) && Package KFX (from KFX Input) (2, 15, 0) && EpubMerge (2, 18, 0) && EpubSplit (3, 7, 0) && KFX metadata reader (from KFX Input) (2, 15, 0) && From KFX (2, 15, 0) && KFX Input (2, 15, 0)
Traceback (most recent call last):
  File "calibre_plugins.epubsplit.epubsplit_plugin", line 147, in plugin_button
  File "calibre_plugins.epubsplit.epubsplit", line 733, in get_split_lines
  File "calibre_plugins.epubsplit.epubsplit", line 655, in get_toc_map
AttributeError: 'NoneType' object has no attribute 'getElementsByTagName'

I'm running a current version of Windows 11.