Yes, I am still getting the error when I use the customise theme menu.
Here is the screengrab of the popover. https://www.dropbox.com/s/7yfx46sd6nlxbg4/Screenshot%202020-05-08%20at%2011.34.39.png?dl=0
Also, I tried to install languages as per your directions, but when I add a language it doesn’t show the “Save” button highlighted.
Screenshot of that: https://www.dropbox.com/s/u3yqyp043teuk0n/Screenshot%202020-05-08%20at%2011.34.53.png?dl=0
