After Effects Render Artifacts

[mitchellk87251422]

I've been working on a project and rendering out several sequences combining animation, videos and still photos. I need to render them with alpha channels, as they usually overlay onto other footage. The renders have been fine up to around yesterday, and now every single one has this weird pixellation happening across the screen.

I'm not even sure if it's visible there, but it's like rows of pixels that pop in for just a frame or two, then disappear, but it happens consistently through the render.

I'm rendering with RGB+Alpha using Apple Pro Res 444. I've tried clearing my cache, going up to 16 and 32 bit, taking my sections out of precompositions. I don't know what else to try. I don't know why this is suddenly happening now, all of my other renders have been fine.

I really hope someone has a solution! I don't know what to do!

Thank you

[Rene Andritsch]

As you have many different types of assets this might be difficult to identify. Did you render with the Render Queue or Adobe Media Encoder? Which version of After Effects are you using?
Have you tried hiding certian layers and rendering again to identfiy what causes it. Does it always occur at the same time in the video?

[mitchellk87251422]

I used the render queue, my version of After Effects is 17.1. I know this is an old version, but my computer is quite old and I can't update it anymore.

I've rendered out several versions, trying to identify which layer it could be assosiated with, but so far no luck.

It seems to occur when something else appears on screen, and then flickers throughout.

I've rendered dozens of these sequences with no issue, and now every render I make has these little pixelated lines. I haven't changed any settings since the clean versions.

[Rene Andritsch]

Does all of your imported footage have the same frame rate? Were there any changes to your computer system to the point before this started to happen? Please post your exact specifications. AE version, OS, graphics card(s), RAM etc. 

[mitchellk87251422]

It looks like I've solved the problem. I've been clearing my cache before each render, and it seems to be working for me now.

Thanks for your help!

[Rene Andritsch]

@mitchellk87251422 Glad to hear you found a solution! Just to make it clear for everybody reading this thread. Did keeping the cache solve the issue or deleting the chache?

[mitchellk87251422 · Accepted solution]

I used Edit > Purge > All Memory and Disc Cache before each render.

There were a couple times it didn't work, but when it didn't I would restart my computer, try again, and it seemed to be fine from there.

[Rene Andritsch]

Would you please nonetheless log this in the bug section of the After Effects Support Community so the AE team can see that you had problems with that, thanks. Here is the link: https://community.adobe.com/t5/after-effects/ct-p/ct-after-effects?page=1&sort=latest_replies&filter...

[mitchellk87251422]

Sure thing