DaVinci Resolve 14b3 crashes

First of all, thank you for this great program. It is a huge improvement in the editing and grading of my video's. However when I try to render a clip consisting of a XAVC 50Mbps 1080p clip and some PNG files Resolve crashes very easily, especially when rendering.

I tried converting the XAVC files to DNxHD which improves the editing performance but still I receive quite a few random crashes.

How can I fix it?

Here is my crashlog after a render of a 5 minute segment into DNxHD.