My conversion and testing of 4.6 and FB2 is going OK but I have a really
hard to find exception. The message is

Project PCC.exe raised exception class EIB_ISCError with message 'ISC ERROR
CODE:335544359

ISC ERROR MESSAGE:
attempted update of read-only column
'. Process stopped. Use Step or Run to continue.

If I switch to 1.5.3 on the same database, I get no exception and I can get
an SQL monitor dump of the traffic during the form creation. It shows
nothing untoward e.g. missing aliasing or calculated fields in the update
statement.
The message is curious with regard to '.
i.e. it's not telling me anything about the fieldname.
Stepping thru the debugger is painful. The closest I have got to it is that
it occurs in the SysExecPrepare procedure IB_Components but I'm damned if I
can catch the statement which excepts.

Don't suppose anyone else is going thru something similar?
Alan