Thank you for your response, Mike C.

I can not add a company from the list (Explorer List ie. C:/Xpress12/Company Folder), as the "OK" button is greyed out when trying to do that. Funny thing is, it is doing the exact same thing in v11 as well (I opened v11, to check whether we could open companies in there)... That is what gives me the feeling that it is a database issue...