Hopefully someone who has more knowledge on Lightning will comment, but, I had the same problem and what I had to do to get it working properly was to disable my DSL modem while using Lightning. However after doing that twice I was able to use Lightning withuot having to do disable the modem. Just gremlins I guess ? Anyhow, like I said, there are a lot of people here who use it, and you're sure to get the assistance you require. Best of luck. BTW, when I did get it working it(Lightning) only gave a 20-35% increse in render times,.....I was expecting more.

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