@marcus: Normally, there should be a WYSIWYG-editor right beneath “Choose or upload an image” (screenshot), as on some other pages of the plugin. They appear for a split second though, when loading the page, but then it disappears again. When I deactivate the EM-plugin, it works, as you can see here .
The author of the newsletter plugin said that the cause of the problem was “[that] they should not add their own javascript and css on administration panel of other plugins”.
I must say, I’m not familiar with JS or CSS, so I don’t know if this actually has anything to do with it…
Hope this helps!
Thanks; it got solved in another way 🙂
