Strange bug: content (image) missing for one frame after rendering

[distriller]

I spent many hours with this, rebooting the computer, nothing helps. I have a simple After Effects project with a few layers, containing simple psd/png/jpg images, some masks, some audio, very simple. When I play my composition on the timeline, it shows correctly in the preview screen. However, if I either render the file (to .mp4 for example) or create another composition where I place the initial comp into, in the middle of the video, one layer has an empty frame without a reason!

This has to be a bug. The behavior is totally erratic. If I fiddle around, changing the keyframes a bit (adjusting timing etc.), the problem may disappear without any logical reason. Then, after a few minutes, the problem reappears even it was already fixed several times before. It may have to do with time remapping. Possibly the time remapping has some bug where it renders the exact same thing differently when previewing on timeline and when exporting and when placing a comp into a comp etc.

What's going on? How to ensure this problem doesn't occur?

[Mylenium]

Sounds like simple hardware acceleration issues and/ or cache corruption. Impossible to say much without actual system info, details about the relevant settings and so on. In any case start by checking your hardware acceleration stuff, flush the caches, revert to software-only rendering and so on. Everything else will require more info.

Mylenium

[distriller]

I tried deleting the (huge) caches in After Effects (Media & Disk Cache). I tried software-only rendering in AME. No difference, one frame is incorrectly not showing a graphic element at all. AE shows it in the timeline preview correctly (however sometimes it doesn't show, it's random, but mostly the timeline preview works). 

My computer is HP ZBook Studio 15 G7 Mobile Workstation (HP ZBSG7) and I'm using this (latest, 2022-08-02) NVIDIA driver: 516.94-quadro-rtx-desktop-notebook-win10-win11-64bit-international-dch-whql.exe. What else can I list?

[distriller]

The problematic frame occurs in a place where a layer has been split into two layers. The seam is the problematic frame. The upper layer's first frame is invisible while it logically should not be. Sometimes timeline shows it invisible, until I fiddle around with keyframes, then it changes randomly.

Very strange: I now created a one additional frame to insert a fix to the invisible frame. The fix works so I got the job done. However, now if I pull the layer below to one left, to see what happens, the layer above disappears! So the layer under the fix frame both is invisible (it shouldn't) and it also makes the layer above invisible. Also, now that I made the fix, another frame earlier in the timeline gets a similar vanishing problem in another layer. It's like my project is possessed to ruin my project. What's happening? Mode = Normal and Track matte = None.

[Joost van der Hoeven]

Can you share some visuals? Like what you see in Ae, what you see in your render?

[distriller]

I think I found a way to reproduce this, and I think this is a bug.

Try this: get a .mp4 video (my video is 1920x1080). Simply put it on a new composition, duplicate. For the upper layer: Time / Time-Reverse Layer. Make a seamless transition so that the lower layer ends somewhere in the middle of the video and the upper layer continues from that exact frame.

Now juggle the playback position cursor back and forth to see if the first frame of the upper layer is invisible so that there's a one-frame black frame even there shouldn't be. You may see the bug already. If not, simply export to .mp4 and see the exported. It may have a black frame in the middle even it shouldn't. This may not be 100% reliable way to reproduce this bug, but if you play around like this for a while, at least on my computer it happens in just 1–2 minutes if not immediately.