Although it occurs in the V-Ray core, unfortunately we cannot see in the minidump what is causing the crash. But probably it's the same RC issue.
You can verify it hidding all objects except RailClone and rendering. You can use quick render settings for the test, that will not affect the result.
I just uploaded a temporary patch
in the RailClone forum, bit it's only for the Pro version.
If you confirm the crash is caused by RailClone, try turning off Display->Use instancing engine
in the affected objects. That should solve the problem until we release the final fix.