On the SETTINGS/GENERAL screen I have missing button to Save Changes.
It should appear on the bottom of the screen.
If I change the admin theme do default one button is there as normal.
I checked the console and there is an error related to the chat plugin.
When I disable the chat plugin this error does not occur.
But the button to Save Changes on the main settings page still does not appear.
Also the console says 500 Internal Server Error. And this is only on SETTINGS/GENERAL page.