Visual Editor Media Buttons NOT Working After 4.0 Update

I’ve read the Master List and have done ALL of the troubleshoots (disabled plugins, cached my browser, tried another browser, disabled Cloudfare and other caching plugins) as well as made my host upgrade my PHP version. NA-DA. I’m at wits end.

The media buttons in my WordPress visual editor just add an extra “#” at the end of the URL in the address bar but don’t pop up or do anything. I can add Media in the Media Gallery but the buttons on the editor just don’t work.

I hope someone will be able to help me ?? My host says to restore backup but my last backup was from January ??