CUNY Academic Commons

I recently created https://cuny.is/SPSWritingFellows for https://bacwritingfellows.commons.gc.cuny.edu. It works fine for me but the admin reports "When I go to the link, it works. However, some others have done so and got an error message. (See attached.). I guess this is because cuny.is<http://cuny.is> does not have SSL and the user’s browser is set up to reject insecure websites.

Is there anything that can be done to avoid this? We don’t want students to not get through due to their browser settings."