Note: Location and database name may differ in the error message.
This can be caused by a damaged or missing .ALF file associated with your database while the .ADF file associated with your database is detached from the ACT! SQL Instance. This has also been seen where the .ADF file is listed in the error message instead of the .ALF file.
You can restore a backup to resolve this issue. If you do not have a current backup of this database, you will need to contact ACT! Database Services by submitting a Database Repair Request form and upload your .ADF file to recreate the .ALF file.
Complete instructions can be found on the ACT! Database Services website.