Horizontal green lines in image?

[mermaid]

Hello,
I'm very new to using DCP-O-Matic software and am finding it really good.
But I've been having one main problem. I have been converting MP4 and ProRes files with DCPomatic and it has been working fine. Playback looks good for flat and scope ratios and audio sync is perfect. But every now and then (there seems to be no pattern to this), content will playback with broken up horizontal green lines throughout the image.
Is anyone else having this problem or know what I might be doing wrong?
Any help would be much appreciated,
Eoin

[Carsten]

You should check these DCP in DCP-o-matic player. If these artifacts appear there, too, then it's contained in your DCP and you need to find the reason for it. Possible causes are defects in your source material, or a hardware issue with the PC you used to encode them (e.g. memory or disc error).
For this kind of test, please use 'Decode at full resolution' (even if playback appears choppy then).

Do these artifacts occur totally random, or always in the exact same position in the DCP?

If they only occur on an actual cinema projection system, it could be an issue with that projection system (occasional issues like that happen), but if this projection system shows it only with YOUR content, it may have issues with specific aspects of your DCPs. One possible cause could be a non-compliant frame rate or J2K compression rate (e.g. close to or above 250MBit/s).

- Carsten