We have been working with the Canon C200 for a while, filming Cinema Raw Light, but lateley we sometimes have a (few) white frames in the footage 9nog only on playback, also in export.
When we review the files in the Canon raw player, all is good, within Premiere, all is good, but within FCPX, white frames.
I haven't seen this or heard of it. My team doesn't use Canon Raw Light but ProRes RAW, and we have no problems with that.
I know you've already checked this, but make sure you're on the latest version of FCPX 10.4.8 and verify you have the latest version of Canon RAW plugin, also the latest version of Apple Pro Media Formats. In Mojave and later that is updated via System Preferences>Software Update.
Verify it's not an effect issue: Make a snapshot duplicate of the project, open that and delete all Fx with Edit>Remove Effects. Then disable background rendering in FCPX Preferences, delete all render files, do a one-time render by selecting all timeline clips with CMD+A and render with CTRL+R. If that works it might be an effect issue. If so repeat above but do 1/2 the timeline, then 1/4 to find what effect.
If white frames happen with no Fx and fresh render files, put a test project on locally-attached storage and see if it happens there, vs only on the NAS. If it happens on local storage, state your exact Mac hardware config and we can discuss further.
Thank you for getting back. We have been researching the last weeks and tested different things.
We found out that the Qnap does not work well with RAW footgae impoted over the ethernetcable, so we have imported the footage through the TB3 connection and it all seems a lot better..