This problem is .htaccess file. If there with wp upgradation then there should lot of plugins stop working but no problem in online. This problem is only coming in local server. I didnt find solution but everything will work correct in online.
I have the same issue. I don’t know some authorization problem, Working in my local system as an administrator, looking for solution of this problem from 3 days but got no help. If you resolved your issue please help me.
I tried add_menu_page() in template 2015 but has same issue nothing different from before.
