Cannot perform cascading update on the table because it is currently in use by another user. (Error 3412)

You are trying to save a value into a primary key field that is included in a relationship.

In Microsoft« Access, the Cascade Update Related Fields option is selected for the relationship, or in DAO code, the dbRelationUpdateCascade option is specified for the Relation object's Attributes property. Your application is attempting to update the matching field in the related table.

The matching field cannot be updated because of a locking conflict with another user. To save the record, you must wait until the related table is no longer in use.