SAP Message AM845 - Internal lock error (address can only be displayed)

Diagnosis
An internal error occurred in the lock administration while trying tolock the created address from a competing access by another user.

System Response
The address could not be locked. The address is only displayed becauseaccess by another user could not be prevented.

Procedure
If you wish to process the address furhter, re-start thetransaction and select the addresses to be maintained again.