# 3432 Dropping Foreign Key Constraints Can Cause #401 Error with Database Catalog

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Lately we receive messages from our customers about exceptions in form:

"ElevateDB Error #401 the constraint <number> does not exist in the table <tablename>"

It seems to be a problem with the database catalog file. When we drop constraints as part of our database conversion procedure, for some reason the dropped constraints are still referencing in related tables, this has as a result the tables to be inaccessible.