Hello @quantum ! Thank You for your question.
Unfortunately, this information is not enough to understand what is wrong with the App. Please, send us more information like where does the App stops and maybe attach a screenshot.
If you stream via YouTube, then read this: https://community.h7.org/topic/758/livestream-doesn-t-start where we described what could be the problem of broadcasting on YouTube.
If via Facebook, please read this: https://community.h7.org/topic/762/facebook-live-won-t-start
and this: https://community.h7.org/topic/761/live-stream-won-t-start
It may be helpful.