ORA-01571: redo version string incompatible with ORACLE version string

admin

ORA-01571: redo version string incompatible with ORACLE version string
Cause: This software version can not read the current redo logs, and either crash
recovery is required or there are offline database files that need media recovery. If
a file name is listed then it needs media recovery.
Action: Shutdown and startup using the compatible software. Do any required
media recovery, and open the database. Shutdown and then startup using current

software. If the file is going to be dropped then take it offline with the DROP
option to skip this check.