White flashes in rendered QT Prores movie

I have a 4k timeline that I rendered out to a master file same codec prores 422. The rendered QT file has random white flashes in the playback. I trashed prefs and deleted all render files and ran render again. Same issue...Any thoughts

Let's start with hardware specs, and that 3rd party templates/plugins you're using in that Timeline.

I believe it to be a plugin issue now. I rendered w/o plugins and it rendered fine. I was using the Chromatic demo. I think it may not be full featured in demo mode or uses this flash instead of a watermark. Im going to purchase the full registration and see if that changes anything. I'm also going to use the FCPX color tool for basic adjustments to see if that corrects it.

Chromatic shouldn't effect output at all. Contact their tech support.
support.coremelt.com/hc/en-gb/requests/new

The problem was Chromatic. Once i removed it, the issue disappeared. I contacted their tech support, just waiting on an answer.

It's going to be a GPU hardware issue I bet. Let us know what you find out, please.

Maybe try to reorder your effects in the Inspector. Eg: put the effect that causes issues on the bottom under all other effects (or maybe on top, can't remeber exactly). That worked for me once with Neat Video when it caused similar problems on export...

I only used Chromatic on a test sequence and had the same issue

I figured it out. If I take off the Clamp to legal option, its works fine. If I choose "clamp to legal", the flashing problem comes up. looks like a bug. I emailed Coremelt about what I found.
10.12.6 Sierra/GTX980Ti/32GB RAM/fcpx 10.3.2