- Open the menus (in the admin panel’s left side)
- See the post editors toolbar
- Install new plugins
- Install new themes
I deactivated all the plugins and nothing happened. Then I started looking at the source code and googeling for quite a long time. After some serious research I discovered what caused the issue.
Re upload the
wp-includes\js folder and overwrite whatever is in there.
That’s what fixed it for me.
I hope this helped someone, if it does, or does not – comment to help or get help.