Something wrong with pop-up message in V7.9.9

After updated to the latest version 7.9.9 , every action which would have a pop-up message turn to an error page that the whole page turn to gray and could not do anything as the picture attached here.
For example, after saving the change in studio ,there’s a pop-up message telled “successfully”, then the page turn to gray and I can do nothing on the current page which I could closed the massage in before version.

By the way ,it seems I could not Add File in here with attachments, there’s no response after clicking [Add File].

You can add screenshots in this site and then post the link here

The issue you mention has been reported and fixed for the next release.