Crashing within a minute on v15.0.0B.030

Running Mac OS 10.13.4, free version Resolve 15.0.0B.030, i7 Imac 3.4ghz, 20gb ram
Create a new project, import some clips, begin to preview them by dragging over one, or drag one into the timeline. Nothing specific - app quits without warning. Clips are a mixture of resolutions; 1080 up to 4K. Maybe this is the issue, since the free version doesn't do 4K??

Anyone else seeing this? Is the v15 beta 2 the free version?

[Peter Chamberlain]

Please review
viewtopic.php?f=21&t=69837

We don't see your issue here so without details it can not be reproduced.

My finding is that, mixing HD with 4K causes the crash. Today I was careful to bring only 1920x1080 into a project and all was fine. Soon as I imported a 3840x2160, seconds later, boom. I then started a new project with all UHD, and no crash.

What I'm finding, however, in UHD, something is causing strain on processing. I cannot play back any clip smoothly. They all stutter and skip terribly. Maybe this is subject for another post, but if you have advise Peter, please do tell. i7 iMac 2.93gHz, 24gb ram, High Sierra