Dawn of the Dragons have issued a workaround for those users having issues with Rally Cries and Get help Requests.
For those who have issues with Rally Cries/Get Help requests etc, there is a workaround you can use till issue is solved: When the FB request popup shows up blank trying to load, just right click it and select "Reload Frame". Wait a couple of seconds, and the request should appear normally in the popup. Click "post" and it should show up on your FB pages just fine.
