Random issue using 3D model light in Rhino/V-ray

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I have an issue when rendering a interior shot using 3D lamps from Chaos Cosmos browser. It is super random. I can have two of the same lamps in my scene where the issues only occurs with one of the lamps. Then I delete the "bad" lamp and copy the "good" lamp. But randomly the issue occurs again. And the issue. When I place a lamp in my scene a transparat box with a darker tone occurs. I can turn off the light in my lamp to fix the issue, but I like the idea of the lamps are working. What am I doing wrong?
I have the latest drivers and software installed. I use the 3d models with standard settings. So I do not change any settings. (Except turning of the light in the Asset Editor)