What version of MB are you using? (Help > About) INCLUDE THE LETTER (if any) AFTER THE NUMBER
How was MB installed? (Store, Installer, Portable)
MB doesn't support any Apple devices so how are you trying to sync to the iPhone?
Per your screenshot, the location you're trying to sync to doesn't exist. Either edit to the correct path in MB device settings, or change the path on the iPhone.
It might be helpful if you post a screenshot of the device settings from MB.