Problem of launch on iphone.DeploymentServer.exe can't found MobileDevice.dll

I have got some problem when I launch my app on iphone. The DeploymentServer.exe keep crash, and notify can not found MobileDevice.dll.
My OS is win7 64bit, UE4 is 4.7.6, release version without compile. itune is 12.1.x,11.x also tried.
here is image of itune 11.x, with itune 12.1.x,just switch “iTuneMobileDevice.dll” to “MobileDevice.dll”.
google tell me, these are some version of UE4 has this problem, and I download 4.8.0p2,but the problem still there.
then I download the source code, run DeploymentServer.exe directly, is the same.
I checked the source code.

Value “MobileDeviceDLL” in registry is
C:\Program Files (x86)\Common Files\Apple\Mobile Device Support\MobileDevice.dll
In directory,File is there. I don’t understand why DeploymentServer.exe can’t find it.
pls help!

There was a pull request that I merged late in the 4.8 process which moved the first PathBits.Add(Environment.GetEnvironmentVariable(“Path”)); to the very end of that function. That fix is in Preview 2 and Preview 1, but the code you posted is definitely the old code. Try moving that function to the bottom, build MobileDeviceInterface and then try it again to see if it fixes your issues.