Commit creates empty track

[rockville]

When I commit a track with plugins Pro Tools creates an empty track, the wave disappears in the new track to be replaced with a straight line. One of the plugins in the chains has input and output meters and before commit the output is healthy but after the commit fails and I undo back to the original track only the input shows a signal. I have tried disabling the plugins but the result is the same after I commit. any ideas?