Many iPhone5/6/7 plus users while restoring their iPhone in DFU mode using iTunes(12.7.) are facing issue that iPhone restore fails with error message “iTunes could not connect to this iPhone. The value is missing.” And once the issue happens the phone is stuck on the apple logo. The user tried to hard reset the iPhone but did not help and ‘value missing' and the issue continues to happen and Never gives an option to restore.
The issue is very annoying when users forgets the password and put the iPhone in DFU mode, suddenly itune error message pop up ‘The value is missing’ and the iPhone is left behind in stuck state.
To fix issue “iTunes could not connect to this iPhone. The value is missing” please follow below solution/workaround:
Fix 1: iTune reset
Connect iPhone with laptop with iTunes opened. Hard press both home and power button until you see iTunes icon on iphone (~20sec). You will see option in restore and update selection, restore it to factory setting.( make sure you have back up on iCloud to retrieve later on, otherwise you will lose your data). If this does not help, please proceed to next solution.
Fix 2: iTunes update and restore option
iPhone connected to computer -> Now Hard reset the iPhone until the iTunes logo came up-> in iTunes two options should come up in an alert/dialog box, if you want to "Update" or "Restore"->Click Restore.
Then in another alert/dialog box it would ask "Are you sure?" -> Now click on"Cancel" and then click the Restore option that was in the iTunes application window. -> Then you should see that the iTunes options for update and restore are no longer greyed out and you can select restore and your phone should start processing.
Hopefully these steps helped you to fix the issue.