Error 1103 on Retrospect 7.6

I am receiving Error 1103 on Retrospect Pro 7.6. I am using this product for years and never had any problems before. Sometime it states that I am unable to create backup and sometime it cannot create catalogs. The frequency of error seems to be increasing in every use. Other than this, the backing up and restoring of files seems to be working fine. My computer is not connected to any network. How do I get rid of this error? Please help.
