This seems to be a specific issue since we are able to successfully export to XML and FCPXML.
Could you send us an export of your project as well as Capture Logs immediately after the crash to davincihelp (at) blackmagicdesign.com?
For the export of the project, open Resolve and load the project. Go back to the project manager (by clicking on the home button). Right click on the project and export it. You can check all 4 options on the pop up window.
Then try to export to XML. As soon as Resolve crashes run the CaptureLogs.app (located at /Library/Application Support/Blackmagic Design/DaVinci Resolve/CaptureLogs.app). This will save a packaged log file on your desktop. Please send us the log file as well as the project export.
It was operator error of some sort. It is working right now except that after exporting the xml file (after rendering the timeline) the re imported xml file into FCPX links to the not graded clips.
I am sure I am doing something wrong but I do not know what.