Rated 2 out of 5 stars
Strangely, I only get the HTML source view with NEWLY created mail, not when editing a replied or forwarded mail. With the latter, the HTML source tab is simply blank :(
(Everything used to work in TB 3, but now not anymore in TB24)
Works for me.
If You have a problem like this, You should just report it to me. The email to support is on add-on page, but I repeat it again here: email@example.com
I usually fixing bugs fast, and Your report could help other people... Now I know there is problem, but I can't replicate it, and I can't contact You... So Your review is basically useless.
I hope that You will read this reply, and You will contact me so we will be able to work on this bug and fix it.