> Most likely bitness of plugin DLL doesn't match bitness of fbclient.
Both 64bit. In fact I'm using same "installation" for server and there it works fine. Callback.dll: File Version Information: File Version: 1.0.0.1 Product Version: 1.0.0.1 File Type: 0x00000002 (Dynamic-link library) File Subtype: 0x00000000 File Flags Mask: 0x0000003F File Flags: 0x00000000 String File Information: 1033 (English (United States)) CompanyName: IBPhoenix FileDescription: AES128 database encryption plugin FileVersion: 1.0.0.1 LegalCopyright: IBPhoenix ProductName: IBPhoenix database encryption plugin ProductVersion: 1.0 File Header: Machine: 0x8664 (AMD64) Number of Sections: 12 Time Date Stamp: 0x56BB615F (10.02.2016 18:12:15) Pointer to Symbol Table: 0x00000000 Number of Symbols: 0 Size of Optional Header: 0x00F0 (240) Characteristics: 0x222E File is executable Line numbers stripped from file Local symbols stripped from file App can handle >2GB addresses Debugging info stripped from file in .DBG file File is a DLL fbclient.dll: File Version Information: File Version: 3.0.2.32703 Product Version: 3.0.2.32703 File Type: 0x00000001 (Application) File Subtype: 0x00000000 File Flags Mask: 0x00000002 File Flags: 0x00000022 Prerelease Special build String File Information: 1033 (English (United States)) Comments: This product created by the Firebird - All Copyright (c) retained by the individual contributors - original code Copyright (c) 2000 Inprise Corporation and predecessors. CompanyName: Firebird Project FileDescription: Firebird SQL Server FileVersion: WI-V3.0.2.32703 InternalName: Firebird LegalCopyright: All Copyright (c) retained by individual contributors - original code Copyright (c) 2000 Inprise Corporation ProductName: Firebird SQL Server ProductVersion: 3.0.2.32703 SpecialBuild: Firebird 3.0 File Header: Machine: 0x8664 (AMD64) Number of Sections: 6 Time Date Stamp: 0x58D0ED79 (21.03.2017 11:08:09) Pointer to Symbol Table: 0x00000000 Number of Symbols: 0 Size of Optional Header: 0x00F0 (240) Characteristics: 0x2022 File is executable App can handle >2GB addresses File is a DLL -- Mgr. Jiří Činčura https://www.tabsoverspaces.com/ ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel