why doesn't my Microsoft Office work any more?

ICGWA wrote:

I already bought the software. I do not want to buy it again. I am a senior citizen and only need it occasionally. Maybe updating my Mac was a bad idea. I would rather have my software working. I don't care about updating my MS Office. It was fine. Am I alone in feeling like this? This doesn't seem right.

or try an alternative for word documents—

Pages.app built into the macOS https://support.apple.com/pages

LibreOffice shareware/ https://www.libreoffice.org/download/download/

Microsoft does not provide free upgrades between major versions of their Office products (unless you subscribe to Microsoft 365) and older versions of Office are not compatible with macOS Catalina or Big Sur.

If you have a version of Microsoft Office that is not compatible, you can either subscribe to Microsoft 365 or you can make a one-time purchase. See: https://products.office.com/en-us/buy/compare-microsoft-office-products-for-mac?ms.officeurl=mac-compare-redir

Or use the free and very good Libre Office https://www.libreoffice.org/

or the free Microsoft Office on the web: https://products.office.com/en-us/free-office-online-for-the-web

or Google Docs: https://www.google.com/docs/about/

or Apple’s Pages and Numbers

ICGWA wrote:

I already bought the software. I do not want to buy it again. I am a senior citizen and only need it occasionally. Maybe updating my Mac was a bad idea. I would rather have my software working. I don't care about updating my MS Office. It was fine. Am I alone in feeling like this? This doesn't seem right.

You'll have to talk with Microsoft about their licensing and upgrade policies. Their licensing does not include free upgrades. If you choose to change your system which then causes your Microsoft product to no longer work that is your choice. Neuther Apple nor Microsoft are responsible for your actions which caused Office to no longer work for you.

My original reply listed 4 free alternatives.