ORA-06510 PL/SQL: unhandled user-defined exception

All:
This is in an old version of Oracle 7.3.4

I have the following simple PL/SQL program:
=================================================
DECLARE
fileHandler UTL_FILE.FILE_TYPE;
BEGIN
fileHandler := UTL_FILE.FOPEN('/tmp', 'myfile', 'w');
UTL_FILE.PUTF(fileHandler, 'I am writing to a file!!!\n');
UTL_FILE.FCLOSE(fileHandler);
EXCEPTION
WHEN utl_file.invalid_path THEN
raise_application_error(-20000, 'ERROR: Invalid path for file or path not in INIT.ORA.');
END;
/

I keep getting the following errors:

ERROR at line 1:
ORA-06510: PL/SQL: unhandled user-defined exception
ORA-06512: at "SYS.UTL_FILE", line 85
ORA-06512: at "SYS.UTL_FILE", line 120
ORA-06512: at line 4

BTW> I do have write permission to the directory and UTL_FILE_DIR=... is in my init.ora file.


Any suggestions?
Thanks,

Can you post the output of the following SQL?

select * from all_directories

Also, PUTF needs format.
PROCEDURE UTL_FILE.PUTF
(file IN FILE_TYPE
,format IN VARCHAR2
,arg1 IN VARCHAR2 DEFAULT NULL
,arg2 IN VARCHAR2 DEFAULT NULL
,arg3 IN VARCHAR2 DEFAULT NULL
,arg4 IN VARCHAR2 DEFAULT NULL
,arg5 IN VARCHAR2 DEFAULT NULL);

Tamil