QGPL should be in the *LIBL during install/upgrade.

A couple of times a customers have contacted us because of an upgrade of InterForm400 which halted with an error.

When digging into the message it was a CPF4101 stating that QPRINT was not found in the library list.

It turned out, that the upgrade was done without the library, QGPL in the library list (and this is where the QPRINT printer file was found).

Such a situation is VERY rare, but if you should get this error I would suggest to check out the library list and then try the upgrade again.