Unable to open backup log '%1'

Error constant SQLE_UNABLE_TO_OPEN_BACKUP_LOG
ODBC 2 State OK
ODBC 3 State OK
Parameter 1 Backup log file name.
Severity 10
SQLCODE 119
SQLSTATE WB011
Sybase error code 13776
Probable cause

The server was unable to open the backup log to record the execution of a BACKUP or RESTORE statement. Check the settings of the environment variables used to locate the backup log file. The directory to contain the log must already exist.