Looks like a CSS bug/incompatibility. Usually these are not related to TinyMCE Advanced (this plugin), but are caused by other plugins that may be partially incompatible with the classic editor.
Could you try right-clicking on the large empty space and selecting “Inspect” or “Inspect element”, then look at the styles applied to the editor toolbars. Note where the styles come from, i.e. are they the default WP styles or are some of them from a plugin.
If that sounds too complex, make few more screenshots that include the browser tools (they open when you select “Inspect”), so I can try to figure it out.
Were you able to look at my screenshots?
Yeah, looked there couple of times but unfortunately cannot determine where the error is coming from.
It is most likely CSS related. The TinyMCE toolbar script (that sets the UI) gets the wrong height for the top toolbar. Maybe try looking inside of the div with height=”576″ as seen in this screenshot: https://www.dropbox.com/s/ge1684g6o8n10xb/Screenshot%202020-04-19%2012.23.11.png?dl=0 (highlighted in blue). Perhaps one of the buttons inside of it has the wrong height and that makes the whole toolbar container div too tall.
I’ve been having the same issue. Only in my case, the height=”589″. It doesn’t do this until the post is first saved.
If anyone discovers the cause, I’d like to know.
I think this post will help you. I used to have the same error as you, I have followed the instructions of this article and have fixed the above error.
See more: http://www.congthuc.vn/threads/tinymce-advanced-edit-post-error-loi-khong-thay-noi-dung-khi-sua-bai-viet.2959/
