I have tracked down very similar issue / second part of the issue:
ASSERT: "last >= first" in file kernel/qabstractitemmodel.cpp, line 2392
tracked down the guilty file is calibre/gui2/tag_view.py, in which for 3 times
beginInsertRows is used with last parameter lesser than second one, this is now forbidden in latest Qt.
(
here at line 2393, the assert)
Still I haven't enough time to fix, sorry
Code:
/usr/lib64/calibre/calibre/gui2/tag_view.py:1266: self.beginInsertRows(category_index, 999999, 1) #len(data[key])-1)
/usr/lib64/calibre/calibre/gui2/tag_view.py:1299: self.beginInsertRows(category_index, 999999, 1)
/usr/lib64/calibre/calibre/gui2/tag_view.py:1335: self.beginInsertRows(category_index, 999999, 1)