Sharing Run Mode Not Working

I have tried run mode with two different projects with same results. They run on my system but simply show the loading widget spinning endlessly when I email the URL to a friend or tablet. I am working on a project for hire and need to send a working run URL to some people. I did not have this problem with a previous project which has been published and is working fine. But now the previous project run mode doesn't work either when I email it. If I email either run mode URL to myself they work on the original system. Need to resolve this ASAP.