I've been having a ton of troubles with ios over the past few weeks. I finally was able to test on my ipad tonight. I don't know if this will work for everybody, but hopefully it will save someone from banging their head against the wall

1. (one of Justin’s solutions) Downloaded haxe 3.4
https://haxe.org/download/2. Opened the Terminal application (do a search and type in Terminal)
3. Once the prompt was up, I typed:
haxelib setup
4. When prompted for a location, I pressed Enter for the default location
5. I also did:
haxelib install
... with the following libraries:
nme
lime
hxcpp
hscript
swf
I do not think you actually have to do those, I just wanted to be safe.
6. (one of Stefan’s solutions) Grabbed Xcode 8.2
https://developer.apple.com/download/7. (opposite of what someone else's suggestion about provision profiles) In Xcode > preferences > account > profile list, I actually deleted the provisioning profile that was already there.
8. I compiled from stencyl to get an xcodeproject
9. I opened the xcodeproject and then ran to iOS device.
10. After a few seconds, the xcodeproject screen reverts to default. After that happened, I then clicked “Automatically manage signing”, waited for the team prompt to appear and put in my name. Most of the other fields filled in automatically. The only one left was clicking “capabilities” and fixing the GameKit key.
All of this was done without any certificates, provision profiles nor the team identifier filled within the Stencyl settings. I did not have to do anything with the actual p12 or mobileprovision files and probably did not even have to download them.