Answers.Body: <p>I fixed this issue by changing the renderer from OpenGL to Software based. The problem is still there when previewing in the timeline, but it's gone after exporting.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-10-17T11:33:01.287Z
Answers.LastActivityDate: 2018-10-17T11:33:01.287Z
Answers.UserDisplayName: skillz21
Answers.Body: <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>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-10-16T13:55:05.643Z
Answers.LastActivityDate: 2018-10-16T13:55:05.643Z
Answers.UserDisplayName: tomh
Answers.Body: <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>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-10-16T19:23:49.477Z
Answers.LastActivityDate: 2018-10-16T19:23:49.477Z
Answers.UserDisplayName: Inan
Body: <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.sstatic.net/ejkJD.png" rel="nofollow noreferrer" title="Ignore that circle near the neck"><img src="https://i.sstatic.net/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.sstatic.net/Dffxb.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/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>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2018-08-24T10:30:33.217Z
Comments.Text: Dose same thing happen, when you export your video? Most probably it is just "preview" thing, because your system can't handle KeyLight for 4K in realtime. Try to flush your media cache, it can help, is preview was rendered wrongly
Comments.UserDisplayName: Shultc
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2018-08-24T10:31:41.903Z
Comments.Text: @Shultc It happens a lot in the preview, but, for the first time, I had it happen after I rendered as well.
Comments.UserDisplayName: skillz21
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2018-10-17T11:19:15.210Z
Comments.Text: Is it just one single frame or more than one frame when you render?
Comments.UserDisplayName: Capogear
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2018-10-30T10:44:29.810Z
Comments.Text: @Capogear I solved the issue! I have already written an answer down below, thanks for taking your time to check out my problem :)
Comments.UserDisplayName: skillz21
Tags: <after-effects><greenscreen>
Title: Why does this clip go green and how do I fix it?
UserDisplayName: skillz21
ThreadText: # Why does this clip go green and how do I fix it?
  
  (Asked by: username_0 on 2018-08-24)
  
  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):
  [![enter image description here](https://i.sstatic.net/ejkJD.png "Ignore that circle near the neck")](https://i.sstatic.net/ejkJD.png "Ignore that circle near the neck")
  
  Anyway, but in some frames, towards the end of the video, the shot flashes briefly to this and back to the original:
  [![enter image description here](https://i.sstatic.net/Dffxb.png)](https://i.sstatic.net/Dffxb.png)
  
  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?
  
  **Tags:** after-effects, greenscreen
  
  > **Comments:**
  > **username_1**: Dose same thing happen, when you export your video? Most probably it is just "preview" thing, because your system can't handle KeyLight for 4K in realtime. Try to flush your media cache, it can help, is preview was rendered wrongly  
  > **username_0**: @username_1 It happens a lot in the preview, but, for the first time, I had it happen after I rendered as well.  
  > **username_2**: Is it just one single frame or more than one frame when you render?  
  > **username_0**: @username_2 I solved the issue! I have already written an answer down below, thanks for taking your time to check out my problem :)  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_0 on 2018-10-17. Score: 0 | Accepted answer
  
  I fixed this issue by changing the renderer from OpenGL to Software based. The problem is still there when previewing in the timeline, but it's gone after exporting.
  
  
  ---
  
  ### Answer by username_3 on 2018-10-16. Score: 1
  
  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.
  
  
  ---
  
  ### Answer by username_4 on 2018-10-16. Score: 1
  
  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.
  
  
  ---
  
  