Compiling RPGLE using non-keyed file that's using OPNQRYF to specify key fields

Hi, I'm a bit stumped with this one
There's a third party application on our system and we run a process over
one of their files that's not keyed.
We have a CL that does an OVRDBF and OPNQRYF specifying key fields,
We then call an RPGLE to process.
The base file has changed so we need to recompile the RPGLE
I keep getting the following:

Msg id Sv Statement Message text

*RNF7081 30 013500 The File operation is not valid; there are no
common key
fields. The specification is ignored.

I've tried performing the OVRDBF and OPNQRYF scoped to *JOB and compiling
interactively but its having none of it.

Had a search and found a page on Code400 stating this is not possible.
Just confused as to how this program has been running daily for twenty
years.
Debugged the live program and it's the same and does not report any issues
Any help on how I can get it compiled would be greatly appreciated

Regards.
Liam