> A write to an OLD field was not valid syntax in v.1.5, either. So that is much less likely than an AFTER trigger that is trying to assign to a NEW field. In v.1.5, you could *write* a trigger like that but the Fb 1.5 engine would just ignore it. From Fb 2 onward, it causes an outright exception.
>

Unfortunately, I have no such trigger in my database.

> To find the offending triggers you need to do a full metadata extract
> to a file, and search all of your trigger code for an AFTER trigger
> that is doing NEW.SOMETHING = SOMETHING. Then, you need to get
> everyone offline and do ALTER TRIGGER for each one that has the
> problem. You could do that with a script.

I did that already, without success, for both "write to NEW in AFTER
trigger" and "write to OLD anywhere".

Is there anything else that became read-only with FB2?

Pepak