I am not tech savy enough to understand all the ins and outs but I tried changing the firefox settings by making wikitree an exception and received this reply:
Your connection is not secure
The owner of apps.wikitree.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.
apps.wikitree.com uses an invalid security certificate. The certificate expired on Friday, April 15, 2016 11:47 PM. The current time is Tuesday, May 03, 2016 11:37 AM. Error code: SEC_ERROR_EXPIRED_CERTIFICATE