Thank you very much, philetus!!
Unfortunately, Google Chrome (and now followed by Firefox) has “deprecated” their support of industry standard SHA-1 certificates although they are perfectly valid. Their “not secure” message is erroneous in our case. Our SHA-1 certificate is valid and our secure server continues to encrypt our donor transactions as always. You can click on “Advanced” at the bottom of the message and proceed to secure.freerepublic. com or try a different browser if you have one. Edge (the default browser on windows 10), for example, accepts our certificate normally with no warning messages.
He told me he used Firefox next and it worked.