Combining xlsx files asn a pdf

[Jon Polish]

Hi:

I am using Foxit as my default pdf tool. If MS Excel or LibreOffice Calc as default xlsx apps, I can select multiple files, right click and combine them. This does not work with PlanMaker. A message appears saying there is no default app. But there is.

Any ideas about how I can get this to work as it does with LibreOffice and MS Excel?

Thank you.

Jon