correct corruption in magento website shop

I cannot edit products anymore in my magento admin, after (probably) bad coding of another freelancer that didnt manage to do another job and left me with this error in magento. When I want to edit a product in magento I receive following error: Warning: include(Mage/Catalog/Model/Product/Attribute/Source/[login to view URL]) [[login to view URL]]: failed to open stream: No such file or directory in /var/www/vhosts/[login to view URL] on line 73 This can have to do with modules installed on magento: (before the site was working perfectly) fooman_speedster smile module for openerp however I have no idea where it comes from, the guy who was working on the site doesnt show up anymore, and I am desperate to get it fixed ASAP.