uncaught exception in generating ODE visualization

[soonho-tri]

from Jon's bicycle model.

[soonho-tri]

This is what happens:

1. All ODE pruning failed and we had 'vacuous' delta-sat as a result.
2. Since --visualize option is on, visualization generator tries to get an actual trajectory from the delta-sat assignment. The exception is thrown here (from ODE solver).