Hi
Welcome to the MYOB Community Forum, I hope you find it a valuable resource.
If you have free file licences under your serial number, you can go ahead and activate a new company file using this serial number. Otherwise, you can either de-activate unwanted files to make room, or purchase additional file licences. I've sent you a forum private message requesting additional account information, if you can reply to it, I can check it further for you.
In terms of exporting reports, what happens exactly when you try to export any report? Was there any error message? If so, was this the error you received? - Error: "Unable to locate the necessary files to perform this OfficeLink function"
Please do let us know how you go.