The field "automatic number" type changed in Access cannot be changed back! (Resolved)
When the auto-increment field in access is changed to a value and then to an auto-increment field, the following message is displayed: After data is entered in the table, no field data type can be changed to "auto-numbered, solution:
1. Right-click the table, design it, and open the field design status.
2. Delete the auto-increment field you want to change.
3. Add a field at the end (with the same name as the Deleted field) and set it to an automatic number.