PDF will not open in Adobe

I have installed an older version of Adobe because when I click on the PDF link it gives me an error. I have had the newest version, but it says I need an older one; "To view the full contents of this document, you need a later version of the PDF viewer. You can upgrade to the latest version of Adobe Reader from www.adobe.com/products/acrobat/readstep2.html"

I can see this was last updated in 2018 - perhaps you need to update this version on your end? Thanks