Intermittent “Unable to allocate memory” error in After Effects, but succeeds on retry

[manav_5104]

We are encountering an intermittent After Effects render error:

“After Effects warning: logged one error – After Effects: Unable to allocate 37,641 MB of memory. Either decrease the memory requirements for the rendering of this frame, or install more RAM. (12803 / Unidentified caller).”

What is confusing is that the same composition renders successfully when retried, without any changes to the project, settings, or assets. This suggests that the composition itself should be within memory limits, yet the failure occurs sporadically.

From Adobe documentation, it appears that After Effects may require a large contiguous block of memory when rendering certain frames, and that memory fragmentation or internal memory state could cause allocation failures even when sufficient total RAM is available.

The renders are running on a machine with the following characteristics:

• Instance type: c5.4xlarge (32 GB RAM)

• No other applications running besides After Effects

My questions are:

1. Is there any way to determine actual memory usage per frame or per render attempt within After Effects?

2. Are there known scenarios where After Effects fails due to memory fragmentation or internal memory state, resulting in intermittent allocation errors?

3. Can retrying a render reset After Effects’ internal memory state in a way that allows the allocation to succeed?

4. Are there any recommended settings, diagnostics, or best practices to help prevent or debug this type of intermittent memory error?

Additional details:

• After Effects version: 24.x (After Effects 2024)

Any guidance or insights would be appreciated.

[OliviaHazel]

• Per-frame memory stats?
  Nope. AE doesn’t show memory usage per frame. Best you can do is watch AfterFX.exe in Task Manager (RAM + GPU memory).

• Can AE fail due to fragmentation / internal state?
  Yes. This is a known issue. AE sometimes needs a huge contiguous block of RAM, and fragmentation can cause random failures even when total RAM looks fine.

• Does retrying help?
  Yep. Retrying can partially reset AE’s internal memory/caches, which is why the same render often works on the second try.

• How to reduce this?

  • Turn Multi-Frame Rendering OFF (big one)

  • Purge All Memory & Disk Cache before rendering

  • Pre-render heavy precomps

  • Don’t give AE all the RAM (leave some for “other apps”)

  • Use aerender instead of the UI if possible

Also worth noting: AE trying to allocate ~37GB on a 32GB machine means you’re right on the edge. Intermittent success is exactly what you’d expect in that case.

[nishu_kush]

As suggested by OliviaHazel, clearing media cache (Edit > Purge > All Memory & Disk Cache) should help in such cases.

Let us know how it goes.

Thanks,
Nishu