Oracle Message ORA-01205 - not a data file - type number in header is string

ERRORnot a data file - type number in header is string
CAUSEThe file type in the header is not correct for a data file. This is probably a log file or control file. If the type is not a small non-zero positive number then the header is corrupted.
ACTIONRestore a copy of the correct data file and do recovery as needed.