I updated from impression 1.11 to 1.12 and I'm not able to create a new article or to edit one. (The front end pages works as well.)

My module name is not "impression", it is "aktuell"

This is my error page:

This page cannot be displayed due to an internal error.

You can provide the following information to the administrators of this site to help them solve the problem:

Error: Handler does not exist
Module: aktuell
Name: cat
Backtrace:
/include/functions.php (1997)
/libraries/icms/db/legacy/updater/Handler.php (252)
/libraries/icms/db/legacy/updater/Handler.php (192)
/libraries/icms/db/legacy/updater/Handler.php (425)
/modules/system/admin/modulesadmin/modulesadmin.php (1517)
/modules/system/admin/modulesadmin/main.php (247)
/modules/system/admin.php (76)

Developer Dashboard
None | All | Errors (3) Queries (412) Blocks (0) Extra (3) Timers (3) Deprecated (0)
Errors (3)
Unknown: Assigning the return value of new by reference is deprecated in file /www/my_trust_path/modules/protector/class/ProtectorFilter.php line 88
Warning: constant() [function.constant]: Couldn't find constant AKTUELL_DB_VERSION in file /libraries/icms/db/legacy/updater/Handler.php line 405
Error(s): Handler does not exist
Module: aktuell
Name: cat in file /include/functions.php line 1997