Hello Joje
I hade the same problem You have to choose the client library from a other directory than < c:\program files\firebird\firebird_3_0 > May you choose <C:\Windows\SysWOW64\FBCLIENT.DLL > You have to set this in the Host Registration Info under the register connection / client library! Best Regards Gregor Von: firebird-support@yahoogroups.com [mailto:firebird-support@yahoogroups.com] Gesendet: Mittwoch, 26. Oktober 2016 15:33 An: firebird-support@yahoogroups.com Betreff: [firebird-support] Unable to upgrade database to firebird 3.0 Hello All, Recently I upgraded my Firebird from 2.5 to 3.0 and I am using 'EMS SQL Manager Interbase/Firebird' to connect and work with database. Now whenever I connect existing database or register a new database I get following error Unsuccessful execution caused by system error that does not preclude successful execution of subsequent statements. Error loading plugin Engine12. Module C:\Program Files\Firebird\Firebird_3_0\plugins/Engine12 exists but cannot be loaded. SQL Code: -901 IB Error Number: 335545004 I visited EMS website and found there latest version supports upto Firebird 2.5 . Could someone suggest another method to connect to database. Thanks in advance. With Regards, Joje T. George