ERROR: Could not connect to lockdownd, error code -21

Getting Started Newbie Questions
#1

I am trying to deploy to an iOS device and getting the following error when it tries to copy the build to the device.  I have tried several devices and get the same thing.  The devices are connected to the computer and recognized by iTunes.  This worked the last time I tried a few weeks ago.  I just upgraded to the latest stable build (2906) and still having the same problem.  Anyone know how to fix it?

Sep 17 02:06:02.127 ERROR: Could not connect to lockdownd, error code -21

                    ERROR: Could not connect to lockdownd, error code -21

                    ERROR: no USB connected devices detected (if one is attached, try reconnecting it)

Sep 17 02:06:02.499 ERROR: App Installation Problem: *ideviceinstaller* encountered an error installing the app:                    

                    ERROR: ERROR: Could not connect to lockdownd, error code -21

                    ERROR: Could not connect to lockdownd, error code -21

                    ERROR: no USB connected devices detected (if one is attached, try reconnecting it)

#2

I are you using Xcode 8? I think you have to Xcode 8 with iOS 10. I got the error when I first got it

#3

I am deploying for iOS 9.3.4.  I am on XCode 7.3.1, so I will upgrade that to see if it makes any difference.

#4

I just noticed you said the word stable build. I recommend using a daily build on top of lastest version of Xcode and iOS 10. It may take Xcode a long time but this is one of those times I recommend updating everything

#5

Upgraded everything to most current versions as recommended and now working fine!  Thanks!

#6

Thanks was getting the same error will try using the latest daily build

#7

I are you using Xcode 8? I think you have to Xcode 8 with iOS 10. I got the error when I first got it

#8

I am deploying for iOS 9.3.4.  I am on XCode 7.3.1, so I will upgrade that to see if it makes any difference.

#9

I just noticed you said the word stable build. I recommend using a daily build on top of lastest version of Xcode and iOS 10. It may take Xcode a long time but this is one of those times I recommend updating everything

#10

Upgraded everything to most current versions as recommended and now working fine!  Thanks!

#11

Thanks was getting the same error will try using the latest daily build