Channel Tools has stopped working *** SOLVED ***

Have you accidentally made the track mono?  It will only work on stereo tracks. 

YAY....I helped someone :-)

I've done it a few times myself.

Glad I could help. 

I'm a Channel Tools fan. Lots of helpful stuff can be accomplished easily with it.

No phase invert button pressed. I just could never grow to like what it does.

im a channel tools junky myself, critical for bringing a tracks that's buried in a mix out in the open.
when frequency's are being hogged up in the spectrum and you run out of panning options it works great.

your not alone on this one thought bj, this happen to me for the first time a few weeks ago, it took me awhile to figure out it was a mono source.

Mid/Side processing alone shouldn't change what you see on the correlation meter, because it doesn't alter phase. Of course, any mono-compatibility problems that already exist can be exaggerated by raising the gain on the Side component. That's probably what's happening.

Channel Tools does have a much-abused preset called "Increased Width". What this does is add a 20ms delay to the right channel, emulating the Haas Effect. It shouldn't introduce mono-compatibility problems, but if you were to reduce the delay you'd likely hear some comb filtering when you folded it to mono. There is another preset called "Kill Center" that most definitely causes problems and makes things disappear because it inverts the phase of the right channel.

Although CT is useful for special effects (some not mono-compatible), the only time you really SHOULD use it is for stereo panning. Never use the Pan slider to position a stereo track; always use Channel Tools to do that. It will not have any negative impact on your audio unless the track has already been screwed up by some other processor.