This hint with the frames was a clou!
These frames are created at runtime and I checked the wrong list in my project inspector.
Your question made me aware of that.
This is corrected thing:
Now my DBModul is REALLY created at the first place and I am one error-message step further.
It reads:
[Debuggerausnahmen-Nachricht]
[Break]
Projekt project_Tiger hat Exception-Klasse »EIBInterBaseError« ausgelöst mit der Meldung:
Engine Code: 335544472
Your user name and password are not defined. Ask your database administrator to set up a Firebird login
In Datei 'IBDatabase.pas' in Zeile 1082
[Diesen Ausnahmetyp übergehen]
[Continue]
Which means to me in other words:
"Key in user name and password somewhere."
But where exactly? (pls see the list of what I have in my first posting)