Applying a mask or crop to a clip on the timeline causes the clip to turn green and snowy

Hello ​@John_ZG,

I couldn’t get a project to reproduce this on our end, but I’d like to confirm a few things. 

1. Was the project made in 26.2, had the issue, then you upgraded to 26.3 and still had the issue with the same project?
2. How did you import the Red footage? Did you try using the Media Browser in a new project created in 26.3?
3. Does setting the Program Monitor to Full before adding the Mask make any difference?

If you’re willing to send us the project with this issue and just the clip that turns green, feel free to DM me and I can provide a private upload link I could share with our team internally. We would really appreciate a deeper look to see what could be causing this.

I also hate to be the bearer of bad news, but we should look at upgrading the system before 27 is released. 

I don’t think that’s causing an issue here, as I too have an intel based iMac and tried various things to try and reproduce this issue without success on it, so there’s something else at play here. 

Thank you for bringing this to our attention,

Amy