Deletion of pages does not work

If you try to delete a page at https://vpro0100.proserver.punkt.de an execution is thrown

"Exception
An exception occurred while executing 'SELECT `uid` FROM `tx_certifications_domain_model_certificate` WHERE (`pid` = ?) AND (`tx_certifications_domain_model_certificate`.`deleted` = 0)' with params [90]:

Table 't3o.tx_certifications_domain_model_certificate' doesn't exist"