XF 1.2 Lost My BackEnd (Admin)


I just installed the latest version of Xenforo and then imported all my files from vB to it.I then proceeded to delete vB and replaced the folder contents with Xenforo. Everything is fine so far but when I come to log into the backend - MyAdim area of Xenforo - I get an error. Anyone knows how I can restore the Admin area or do I have to do a new Install?