I’ve had similar issues a few times, most of the time it’s a bugged or old plugin or some kind of file permissions issue with render files or optimized media.
Are FCPX and ColorFinale or any other plugins updated to the latest version?
If you’re using ColorFinale only for applying LUTs you could just use the built in Camera-LUT function in FCPX instead (in the info inspector, metadata-view general).
You could export an XML of your timeline, create a new library and import the XML into that.
You could try deleting the cache files manually. It’s either a ***.fcpcache file in the cache storage location you specified, or the “Render Files” and “Analysis Files” Folders inside the fcpbundle if you have set the location to “In Library”.
I would not burn directly to DVD disk or image but render a ProRes master and encode that via Compressor or reimport it to FCPX, then do DVD export.