After pulling the latest ET, it appears that practically all of my parameter files no longer work. The reason is simple:
ML_BSSN::LapseACoeff and ML_BSSN::ShiftBCoeff were removed in the McLachlan rewrite and not properly deprecated like all other renamed parameters.
I found this because it broke the IllinoisGRMHD test suite. I am surprised and worried by my finding, because it appears that no other test suite parameter files set these ML_BSSN gauge parameters, so this was not caught earlier.
Perhaps to prevent this from happening in the future, perhaps in some subset of our tests we should manually set all parameters in the test parfiles to their defaults. This way any bug in renaming parameters will be caught immediately.