I went to manage the system processes and killed all of those related
to Mathematica. I restarted the computer several times. I prayed to a
number of gods. What is wrong? For now I will try to start using
another system, but this makes me sad because I love Mathematica so much.
Call Wolfram Tech Support with your Mathematica licence number in hand
and ask. They will solve the problem.
Joe Gwinn