Hello,
This situation could be caused by a number of situations such as a recent modification to the AstorAddIn.mdb file or moving a data folder or subfolder to a different location. The first course of action would have to be testing your current database file and if you have a back-up of the original astoraddin.mdb, do a roll-back. If you have customized your astoraddins for quite some time, to pinpoint the problem I would run your current data file parallel with an original copy.
Thank you,