It's against all odds that SH3D suddenly crashes on two different computers. To me, this suggests that something else is happening, or has happened.

Did you copy the *.sh3d file? (read: corrupt *.sh3d file)
Did you import a model shortly before your last use? (read: corrupt or faulty OBJ or DAE model)
Did you install the same update on both computers?

There must be some sort of explanation why both computers have this problem.

Hans