NaN pixels in After Effects 2025 32bits

[J5DDE]

I've been getting multiple NaN pixels lately since updating to version 25.1, with a normal workflow that I have used for years.

I cannot clearly find what's causing the problem, since it randomly appears and disappear. I'm just getting random NaN pixels that expand masively when blured, etc. From my brief experimentation, I believe the appartion of NaNs has something to do with the "Repeat Edge Pixels" feature of some effects (such as Minimax, Channel Blur or Fast Box Blur), but sometimes it persists after removing all that. Sometimes I just hide any layer and the NaN pixels disappear, but the layers by themselves do not seem to have any NaN pixels. Sometimes I just add a Levels effect to a Black Solid layer I'm using as a Matte and the NaNs disappear. It's very hard to pin.

Unfortunately, I do not have a comp I can share because I'm working for a client and in a very tight schedule, but I wanted to report the bug in case this is happening to other people and hoping we can get a fix for it soon.

For now, since I render in image sequences, I am detecting the NaNs post-render, adding a plain Levels effect to any layer and rendering just the previously bugged frames without NaNs. I do this becaus if I render the whole thing again, the NaNs will just appear in different frames. It's not even close to an ideal solution, but I couldn't figure out anything better. If anyone has any ideas...

[J5DDE]

Hi everyone! It's me again. 

In case someone else falls in this rabbithole, here's an update of what I discovered:

I'm getting NaNs when I have my "Main plate layer" tracked-matte to some "Matte layer" and then I try adding any new layer UNDER THOSE. If I try adding, for example, a solid mask at the bottom of the comp, the NaNs start to appear. However, and here is why I wanted to share this, I discovered that the NaNs disappear if I precomp the layer underneath. If I want to add said solid mask under the main plate+matte combo, I need to precomp the solid mask and then I can add it underneath. The overall look is the same and I don't understand why it works when precomped, but it does.

Hope this info helps someone! And maybe someone can explain why layers act different when precomped.