Can't Edit Note. Why?

I was trying to edit a note about the book "Statistics of Financial Markets: An Introduction" in a private list and after I created it, I couldn't edit it anymore. Anything about this bug?

Thanks.

There was a problem with some of the characters inserted in the list, there were 2 words which appear as 'Denitions' and 'Dierential' the first one I think has a character that is a joined f and i and the second one a joined ff character. I have had to replace those 2 words.

Let me know if it happens again because I've only corrected it for this note.