user21414: I have a 4k clip in after effects, in which I have used the Keylight effect. The shot looks like this (I have to blur the face for privacy reasons):

Anyway, but in some frames, towards the end of the video, the shot flashes briefly to this and back to the original:

This sometimes happens during preview while I am working if I start running out of RAM, but I don't know for sure. Sometimes, the shot stays green like that for quite a while before switching back.
I have had this happen in other after effects projects that were not 4k...
I don't know what is going on. Can someone please tell me how to fix this?

user4426: This happens to me sometimes using Keylight.  I find that if I make a tiny adjustment to the settings (holding down CMD and dragging on one of the controls (eg Screen Gain or Screen Balance), it usually disappears.

user3179: When Keylight acts that way, usually emptying the cache helps. If it doesn't help, just add a new adjustment layer to force everything render again.

21414: <p>I have a 4k clip in after effects, in which I have used the Keylight effect. The shot looks like this (I have to blur the face for privacy reasons):
<a href="https://i.stack.imgur.com/ejkJD.png" rel="nofollow noreferrer" title="Ignore that circle near the neck"><img src="https://i.stack.imgur.com/ejkJD.png" alt="enter image description here" title="Ignore that circle near the neck" /></a></p>
<p>Anyway, but in some frames, towards the end of the video, the shot flashes briefly to this and back to the original:
<a href="https://i.stack.imgur.com/Dffxb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Dffxb.png" alt="enter image description here" /></a></p>
<p>This sometimes happens during preview while I am working if I start running out of RAM, but I don't know for sure. Sometimes, the shot stays green like that for quite a while before switching back.</p>
<p>I have had this happen in other after effects projects that were not 4k...</p>
<p>I don't know what is going on. Can someone please tell me how to fix this?</p>
 4426: <p>This happens to me sometimes using Keylight.  I find that if I make a tiny adjustment to the settings (holding down CMD and dragging on one of the controls (eg Screen Gain or Screen Balance), it usually disappears.</p>
 3179: <p>When Keylight acts that way, usually emptying the cache helps. If it doesn't help, just add a new adjustment layer to force everything render again.</p>
