[v1.8.7] TypeError - OpenNumismat\ListView.py:112

OpenNumismat: 1.8.7
OS: Windows 10 (10.0.18362)
Python: 3.4.4 (32bit)
Qt: 5.5.1
Locale: en

Traceback (most recent call last):
File "OpenNumismat\PageView.py", line 642, in modelChanged
File "OpenNumismat\ListView.py", line 754, in modelChanged
File "OpenNumismat\ListView.py", line 112, in modelChanged
TypeError: %d format: a number is required, not NoneType