When you try to modify a “computed by” field, by changing F_AGEINDAYS( to DATEDIFF(day (which result in the same value), using IBEXPERT, it returns success, but when you try to commit the changes, then it shows the message:

invalid request BLR at offset 125

function f_ageindays is not defined

module name or entry point could not be found

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Changes will be rolled back

Function F_Ageindays has been deleted, but it was there, it was also NOT possible to do this even prior to deleting f_ageindays. It would issue the same “module name or entry point could not be found”.

The thing is that the dll file is 32-bit and the operating system and Firebird 2.5 is 64-bit, too. The database was migrated from V 2.0 to V 2.5 with very special switches using gbak from version 2.5.

gbak did not complain about the functions.

Other views and procedures that did use f_ageindays were edited with the datediff syntax and were recompiled with no problems. It is then computed by fields that can't be modified or dropped, due to probably a trigger (?) hidden there, somewhen, that won't allow the operation to take place.

It doesn't make much sense (the error given), since function f_ageindays should not be part of what the deletion and recreation of the “computed by” field requires.