Fatal Error during update to 1.12 / Pse help (1 reply)

Hi,
i tried to update to Piwik 1.12.
I used the automatic download.
When I triy then the update I get this message:
Critical error during update:
/mnt/webh/d0/98/51193598/htdocs/piwik/core/Updates/1.12-b1.php:
Error trying to execute the query 'ALTER TABLE `piwik_log_link_visit_action`
ADD `custom_float` FLOAT NULL DEFAULT NULL'.
The error was: SQLSTATE[42S21]: Column already exists: 1060 Duplicate column name 'custom_float'

Can anybody help???

Mike