When moving an older AbleCommerce 7 database from SQL 2005 to a newer SQL server, you might run into errors with the ac_searchcatalog full text index catalog file.   SQL 2008 doesn’t store FTS the same way it was done in SQL 2005.
The issue usually appears when you try to restore the database backup from 2005 to 2008 or greater.
To fix it, you have to remove the FTS file associated with the database.   But it’s not part of the SQL backup, so you have a problem if you didn’t copy the index file separately.   Here’s how to get rid of the index file reference.
Go into the old SQL server and run as follows:
SELECT name, ftcatid FROM sysobjects WHERE ftcatid > 0
For each returning table name (which are the tables with Full-Text Index), run this command:
EXEC sp_fulltext_table ‘tblName’, ‘drop’
After all table index references are dropped, get rid of the Full-Text Catalog with:
DROP FULLTEXT CATALOG catalogName
After this is done, don’t forget to remove the file by right-clicking the database, choosing Properties, and then click Files.