Are you signed on as QUSER? You probably should not be.
Whatever account you use, if you do not have specific authority to an object (in this case, a spooled file) you will or should encounter a security violation.
If your account has *SPLCTL authority, you should be able to work with any spooled files.
You probably should NOT change QUSER (which has NO special authorites). Likewise, you should not change any other IBM supplied user profile – except to change the default passwords..