I didn’t understood for what you showed me the log about to access to the ‘Menu Editor Pro’ menu item. You wrote earlier that you have a problem with access to the ‘Dashboard’ menu. Or do the problem is about the access to the other menu item?
Anyway please answer on my questions:
Did you try to deactivate both plugins which you suppose are conflicting? Did it help to get access to the missed menu?
Did you try to activate plugins separately?
Do user loses access to the menu item after some plugin separate activation?