I am upgrading from 10.6.8 to El Capitan. I’m being told that Microsoft Excel and Word won’t work. Any ideas on how to convert?

I have 10.12.5 Sierra. Both Word for Mac 2011 version 14.7.1 and Microsoft Excel 2011 work for me.

I’ve had my Macbook Pro three years and upgrade each time something new is available. Word and Excel always work. I have not created anything in Excel, though. I only receive a few Excel files.