Although for CASCADE to not launch rarely occurs, the most likely cause is that the preferences.vr file has becaome corrupted. The preferences.vr file contains information which CASCADE uses for its initial configuration and if this file becomes corrupted CASCADE will not start.

If CASCADE does not launch the solution is to delete the file preferences.vr from the sub-directory G_CASCADE under your home directory. After you have deleted the preferences.vr file just re-launch CASCADE and it will create a new preferences.vr file for you.