Moved topic to troubleshooting.
I would suggest uninstalling the mod, making a clean save without the mod and without Cass as a companion at the time, and reinstall the mod. If the game continues to crash, then redownload the mod. The mod has no other masters other than FalloutNV.esm so you are not missing any master files.
Also make sure archive invalidation is enabled in your mod manager.
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- Can you figure it out?:
01001110 01101111 01110011 01111001 00100000 01100110 01110101 01100011 01101011 01100101 01110010 00101100 00100000 01100001 01110010 01100101 01101110 00100111 01110100 00100000 01111001 01101111 01110101 00111111