Hi Mark
Are you experiencing the same problems as outlined in
THIS THREAD?
I had the problem myself in X2a, even though it was supposedly fixed in X2.
Here are the screenshots I posted in that thread, do they resemble what you are seeing in X3d?
Until you get more knowledgeable/relevant advice, try my workaround at the time, which was to create a new bus or track and try inserting the Concrete Limiter Module there.