[v1.8.11] TypeError - OpenNumismat\ListView.py:112

OpenNumismat: 1.8.11
OS: Windows 10 (10.0.19043)
Python: 3.9.7 (64bit)
Qt: 5.15.4
Locale: de

Traceback (most recent call last):
File "OpenNumismat\PageView.py", line 652, in modelChanged
File "OpenNumismat\ListView.py", line 742, in modelChanged
File "OpenNumismat\ListView.py", line 112, in modelChanged
TypeError: %d format: a number is required, not NoneType