ORA-00209: control file blocksize mismatch, check alert log for more info
What triggered the Error:
The block size in the control file header does not match the size specified in the DB_BLOCK_SIZE parameter.What should we do to fix it:
Look at the alert log for more information.
If this was not sufficient go over to:
Oracle Official Support Knowledge Center
Or maybe those geeks at: StackOverflow Board
Or maybe those geeks at: StackOverflow Board