So, it's been a 2 months since this error persist on my OpenLP. I already tried to download the newest versions (like the newest V3.1.1), but without a solution. Always happens when i need to select a full chapter for the predicator (Mark 12:1-44 for an example). That's the message that the program send to me after the error:
Traceback (most recent call last):
File "openlp\core\ui\servicemanager.py", line 102, in keyPressEvent
File "openlp\core\ui\servicemanager.py", line 1230, in on_collapse_selection
File "openlp\core\ui\servicemanager.py", line 1247, in collapsed
AttributeError: 'NoneType' object has no attribute 'data'