We can try the following; in Workbench select Tools -> Options; in the Options window select Mechanical on the left. Is “Enable Legacy Solve
an option with a check box? If so check it on. If not select Appearance in on the upper left (in the Options window) then scroll down and turn on beta options. Ok out of the Options. Then open it (Tools -> Options) again and go the Mechanical on the left – now is ‘Enable Legacy Solve’ available? If so check on and ok your way out. Now try the solve and post what happens either way.