[v1.8.13] TypeError - OpenNumismat\EditCoinDialog\DetailsTabWidget.py:872

OpenNumismat: 1.8.13
OS: Windows 10 (10.0.19041)
Python: 3.4.4 (32bit)
Qt: 5.5.1
Locale: it

Traceback (most recent call last):
File "OpenNumismat\EditCoinDialog\DetailsTabWidget.py", line 872, in payCommissionChanged
TypeError: 'method' object is not connected