This was kinda hidden in another thread and since quite a few people didn't actually know how to fix it, I thought I would post here to let more folks know.

Last night I took my dwarf priestess into a Molten Core run. When we got to Lucifron (however you actually spell it), at one point I got mind controlled. Whenever I get mind controlled, the first spell the game decides to fire off is holy fire - nice long casting spell. So I'm sitting there, making the long cast of holy fire and just as it was about to go off, I was dispelled of the mind control. And yet, I was still in the casting animation and still had the full cast bar showing. As a result, I couldn't cast any other spell or even use my wand because "another action is in progress". The way I fixed this (besides just dying ) was to try to logout. You'll leave your custom chat channels, but get the error message "You can't logout now". After I got that message, I had to take damage in order to be fixed, but many others haven't needed that apparently so it could have just been lag or something. After having to do that so often with my warriors to fix the charge bug that then desynchs you from the server, I should have known to try that first, but it just never came to mind.

To sum up, if you're stuck casting a spell forever, try to logout and then cancel the logout (if it doesn't automatically do so for you) and you'll probably be fixed.

I hear that if you click the spell you were trying to cast as well, that'll do it, but I haven't personally verified this.

That did not clear it for me when I got hit with the bug. Luckily for me it was cleared when I got pwned by Luci

You can also try "/console reloadui", since this seems to be interface problem, and that command reloads your UI.

Or sometimes simple ESC button works =]

It's more a Mind Control bug than a Molten Core bug - I've been hit with it in DM West multiple times. The first time, I went to logout, finding no other way to fix it, and the attempt to logout itself fixed it, so I hit "Cancel" right away. Sorry I didn't stress the Cancel last night.

Since I didn't wait the full 20 seconds, I didn't have to deal with the fail-to-logout part.

You didn't need to stress the cancel part because it just wasn't an issue. The second I tried to logout, it told me I couldn't and cancelled it for me. I didn't have to wait the 20 seconds for the failure message to pop up.

Well, that explains it. I have had this happen a couple times with my baby warrior. I would charge a baddie and then find that they were meleeing me from range and even brought adds to do the same. I didn't know there was a well known charge bug. Of course, this isn't the first time clueless would be associated with me so I'm not surprised I didn't know.