Database servers at Version 4.0 and later do not return this error. In earlier versions, its meaning is the same as error -271 with ISAM error code -113. Roll back the current transaction, and run it again when the table has been unlocked.
-534 Cannot open EXPLAIN output file.
The statement SET EXPLAIN ON has been executed, and the database server is trying to open the file sqexplain.out in the current working directory. An operating-system error of some kind prevents it. See the ISAM error code for more information. Look for operating-system error messages that might give more detail. Likely problems include a lack of write permissions in the current directory and a full disk. This error message appears beginning with Version 4.1.