Text widget not working - Invalid value.

When I try to add a text widget I get the options box but when I write in the title box I an Invalid value. warning.

Anything in the text box or title box disappears at that point.

I am unable to leave the preview without deleting the widget or clicking the acknowledgment that I may save work.

I'm on Wordpress 4.8 with GP and the premium plugin both up to date (I had to manually update the plugin)

<br />upload my images<br />

https://ibb.co/eAKMVQ