I pasted a large block of text into a box, and it slows the system down so much that it’s unusable. The rest of the page is unaffected. I have to break it up into smaller parts, which is fine, except it’s just long legal text which all needs to stay together.
Maybe it’s because the text is in German (therefore most of the text is underlined in red), but that seems unlikely.
Not sure how to report the problem to the developers.
