When I view my web pages in Firefox, all the letter y's are missing, but in Safari they are intact.

Thank you very much for your suggestion.  you are correct. My web pages look fine on Safari and Firefox on my MacBook Pro and my iPhone. The problem is with my Mac mini, so I will take that up with Apple support. Thanks again for your dependable service.

Hello rperhardt,

Thank you for contacting us about the letter y missing on your site in Firefox. As a test, try visiting your site on a different computer. Does it happen on another computer too? If it does it may be specific to that machine. 

Thank you,

John-Paul