Cause: When a tablespace is plugged into a database, the tablespace is initially read-only. Oracle converts the header of the plugged-in datafiles (assign them a new creation SCN) when the tablespace is first made read-write. This error occurs when the creation SCN in the file header is different from the creation SCN in the control file, possibly because this is the initial version of plugged-in datafile. See the solution below.

Error solution: Either restore the converted datafile or continue recovering the datafile.