I was having this problem constantly. I found out to fix it (for me at least) was to disable my adblocking software on my phone which is rooted.

Adaway and luckypatcher are the main ones so I went on luckypatcher, re-enabled all ads and cleared the local host file and after restarting I was able to see the popup which said 'continue to game' or whatever it is. For Adaway just disable it and restart.

I hope this helps other users until they fix this problem.