When I turned them on, the control signal in Pitch from WFS2 started going up with no stop. It was like the integrator in the loop was fed with a DC bias. The effect of that was to misalign the MC cavity from the good state in which it was with the only length control on (that is, transmission ~2.7, reflection ~ 0.4).
I don't know why that is happening. To exclude that it was due to a computer problem I first burtrestored C1IOO to July the 18th, but since that did not help, I even restarted it. Also that didn't solve the problem.
At least one problem is the mis-centering of the resonant spot on MC2, which can be viewed with the video monitors. It's very far from the center of the optic, which causes length-to-angle coupling that makes the mulitple servos which actuate on MC2 (MCL, WFS, local damping) fight each other and go unstable.