I have created screen with array field (eg. tagInput widget). I have set up Data Structure with correct child entity and array field but there is weird behavior if I try to save screen.
If I update existing row but only change array field, it gets saved without error.
If I change antyhing in master entity or create new one, it failed with this error:
We found out it was caused by the fact that the array field was defined without excluding it from all fields while there was a state machine on the master entity defined. It then fails even before the statemachine workflow starts becouse the state machine subsystem creates it’s own datastrtucture for master entity (but without the array relation child table present).
So the solution is to exclude the array relation field from all fields and add it only where it’s used. It’s btw. best practice for arrayfields anyway.
The question remains whether we should fix it somehow so that the error message is more explanatory or to somehow handle the situation within state-machine subsystem.