I install the new corona 6 demo and when a put sun + sky and start a render my 3Ds max 21 crash. I tried to reinstall but don’t work
Hello, this is highly likely due to the issue described here: https://coronarenderer.freshdesk.com/support/solutions/articles/12000015667-activation-is-required-each-time-i-start-3ds-max-i-am-getting-crashes-material-editor-slots-are-b
Please try steps 2 and 3 and see if it resolves anything, should the issue persist please submit a ticket through our support page or simply reply here.
Work! Thanks!
Hello I have the same issue, 3ds max crash only when I try to use the sun and sky system on interative render.
And did you try the solution given above? 
Let us know the results!