VERMISMATCH, Attempt to access xxxx with version yyyy, while already using zzzz

Run Time Error: The database file xxxx is currently marked as in use by version ($ZVERSION) zzzz, but the process attempted to access the database file with version yyyy. GT.M prevents this as different versions typically have some incompatibility in their use of the database file. This error may also occur when you make a copy of the database without performing a RUNDOWN and attempt to access it with a newer GT.M version.

Action: If you encounter this error while upgrading a database file, perform the appropriate MUPIP action using the prior GT.M version to ensure that there are no processes/semaphores attached to the database file.

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