Your Arcserve database has become corrupt. You need to rename or delete the database folder in your server's arcserve directory. There should be an emptydb folder at the same directory level as your database folder. Once you have renamed your database folder, create a new folder named database. Next, copy the contents in emptydb to the new database folder. Merge your tape back into this new database, and you should be able to see all the data on your tape. You will need to merge all tapes dating prior to creation of this new database before you can restore.
Creating a new database does not delete your scripts and settings. Only the tape information is lost, and since you cannot properly access that data, it's best to start off clean. Hope this helps.
