CPF0001: Error found on command

What it means

Before a command runs, IBM i checks it. It checks that the parameter values are valid for their types and lists, and it can call a validity checking program that the command's author wrote. Each problem it finds is sent as a diagnostic message, often a CPD message. When the checking is done and errors were found, the system sends CPF0001 as an escape message, naming the command.

So CPF0001 is a summary, not a cause. It means "this command didn't run". The diagnostics before it say why. IBM's own technote for one case shows CPD0037 (automatic or selective prompting not allowed) followed by CPF0001. A CL program had ?? prompting in a command and was run in batch, where prompting isn't possible.

In a CL program CPF0001 often turns into a function check if nothing monitors for it. In an interactive session it appears on the message line.

Common causes

• A parameter value isn't valid, such as a name with a blank in it, a value that's too long, or a value not in the allowed list. A CL variable built with *BCAT that puts a space into a qualified name is a common example.
• A command with prompting characters (? or ??) was run in a batch job.
• A command's own validity checking program rejected the values. These send CPD0006 or their own messages before CPF0001.
• Required parameters are missing, or two parameters can't be used together.

How to find the problem

1. Run DSPJOBLOG, press F10 to show detailed messages, and look at the messages just above CPF0001. They name the parameter and the problem.
2. Put the cursor on each diagnostic and press F1 for the full cause and recovery text.
3. In a batch job, open the job log spooled file with WRKJOB option 4, or WRKSPLF. Find CPF0001, then read upwards.
4. If the command is built in a variable, display the variable's value in debug. The problem is often a stray blank or quote.

How to fix it

• Correct the parameter values named in the diagnostic messages and run the command again.
• Press F4 to prompt the command interactively with the same values. The prompter highlights fields it can't accept.
• Remove ? and ?? prompting from commands in programs that run in batch, then recompile.
• In CL, build qualified names with *CAT or *TCAT rather than *BCAT, and use MONMSG MSGID(CPF0001) where you want to handle the failure yourself.

DSPMSGD MSGID(CPF0001) MSGF(QSYS/QCPFMSG)

Technical reviewer: Albert Joseph, WND Software.

Last reviewed 2026-10-18 by the WND Software team. Written in our own words. For the full reference, check IBM’s documentation for your IBM i release.