After installing on my iphone6 the app asks me to power off my phone because something has happened,

Is there a problem installing this on a iPhone 6 ? It won't complete the on status because of an issue that requires me to power down my iPhone and then power it back on- I do that and then start the app again and it seems to start activating, but then the error message comes back and tell me to power down my iPhone again, I have done this a number of times and the same error messages comes back????? I cannot get past this error message ??????