Die Schwalbe
The search command is not correct.
COMMENTDATE>=20200919 AND NOT K='Hilfsrückzüger' AND NOT K='Kniest-Thema' AND S='Chess Player's Chronicle'
atomic expression must have form 'field = value' [( COMMENTDATE >= $$NUMBER0 AND NOT K = $$STRING1 AND NOT K = $$STRING2 AND S = $$STRING3 S CHRONICLE $$STRING4]