After upgrading from 1.2.2 to 1.2.3 I got the following error:

Fatal error: Cannot redeclare printadmintoolbox() (previously declared in /home/damjanac/public_html/zen2/zp-core/template-functions.php:113) in /home/damjanac/public_html/zen2/zp-core/plugins/admin_toolbox.php on line 161

Before the upgrade I turned off all plugins. How I can fix this error? TIA

You have kept the admin-toolbox plugin which is no longer a part of the zenphoto release. Delete that file (zp-core/plugins/admin_toolbox.php).

That solved the problem. Thank you very much.