Just downloaded XCODE 8 and IOS 10 on my iphone. I am getting some Firebase warnings on Xcode, but read that they were working on it and that you could continue to run simulator on your phone with no problems. The build succeeds but then I get this output on Xcode:
2016-09-15 15:04:54.598607 TheApp[443:51993] [MC]System group
container for systemgroup.com.apple.configurationprofiles path is
/private/var/containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles
2016-09-15 15:04:54.601052 TheApp[443:51993] [MC] Reading from
public effective user settings.
2016-09-15 15:05:00.085676 TheApp[443:52259] 0x174146460 Copy matching assets reply: XPC_TYPE_DICTIONARY <dictionary: 0x174146460> { count = 1,
transaction: 0, voucher = 0x0, contents = "Result" => <int64:
0x17403a0c0>: 29 }
2016-09-15 15:05:00.089032 TheApp[443:52259] 0x170147010 Daemon configuration query reply: XPC_TYPE_DICTIONARY <dictionary: 0x170147010> { count = 2, transaction: 0, voucher = 0x0, contents = "Dictionary" =>
<dictionary: 0x1701467d0> { count = 1, transaction: 0, voucher = 0x0,
contents = "ServerURL" => <dictionary: 0x170146f60> { count = 3,
transaction: 0, voucher = 0x0, contents = "com.apple.CFURL.magic" => <uuid: 0x170258ae0> C3853DCC-9776-4114-B6C1-FD9F51944A6D "com.apple.CFURL.string" => <string: 0x170259fb0> { length =
30,contents = "https://mesu.apple.com/assets/" }
"com.apple.CFURL.base" => <null: 0x1b215fe80>: null-object } }
"Result" => <int64: 0x170225ce0>: 0 }
2016-09-15 15:05:00.089289 TheApp[443:52259] [MobileAssetError:29] Unable to copy asset information from https://mesu.apple.com/assets/ for asset type com.apple.MobileAsset.TextInput.SpellChecker
Updated xcode and all of my pods. Everything works well now. If you are having the same problem try doing that. New versions can come with these problems. Looking for updates regularly after a launch helps get rid of this things.