IOS update breaks USB sync
From CompanionLink Support
NOTE: The recent iOS 8.3 update appears to have locked out iPhone USB access.
We have seen some updates from Apple. We are hoping they resolve this issue shortly. Our team is also watching for a workaround that we may regain access to the device via USB.
Until Apple fixes the USB Access, you may want to switch to secure Wi-Fi sync.
Current status of USB sync fix - FIXED
For the time being, we recommend switching to the wifi sync method. Instructions below.
How to sync via wifi: https://www.companionlink.com/support/kb/Setup_Guide_-_Sync_iPhone_and_iPad_via_local_Wi-Fi