I know this error is infuriating. You're mid-render, your comp is perfect, and then After Effects slams the door with Unable to allocate 2.00 GB of memory (Error Code: 12). It's not your footage, not your plugins, and almost never a sign your machine is dying. It's just AE hitting a wall it shouldn't.
Here's the thing: this error tripped me up the first time too. I spent an afternoon reinstalling everything before I realized the fix was simpler than I thought. This is the exact flow I now use with my team. Start at the top, and stop the moment your project renders clean.
Step 1: The 30-Second Fix - Purge Memory and Clear Cache
AE holds onto tons of RAM and disk cache even when it looks idle. The quickest way to break the logjam is to force a clean slate.
- In After Effects, go to Edit > Purge > All Memory & Disk Cache. This wipes the RAM cache and the disk cache in one shot.
- Wait 10 seconds, then try your render or preview again.
That's it. For many people, this solves the error right there. Why? Because AE's memory manager fragments after long sessions, and a purge collapses those fragments back into usable chunks.
If the error comes back within a few minutes, move to the next step.
Step 2: The 5-Minute Fix - Adjust Memory & Performance Settings
If purging didn't stick, AE's memory allocation is probably set too aggressive for your system. Here's the fix I recommend to everyone:
- Go to Edit > Preferences > Memory & Performance (on Windows) or After Effects > Preferences > Memory & Performance (on Mac).
- Look for RAM Reserved for Other Applications. Set it to at least 2 GB, ideally 3-4 GB if you have 16 GB or less RAM total. AE defaults to 1 GB, which is too low. This reserved chunk is what other apps need, and if AE tries to steal it, you get error 12.
- Also uncheck “Enable Multiprocessing” if it's on. Multiprocessing can cause this exact error when multiple frames try to allocate simultaneously.
- Click OK and restart AE.
This fix is the real workhorse. Most people who get this error repeatedly are running with the default 1 GB reserved, which is fine for small comps but chokes on anything with a few layers of effects.
Still getting the error after a few minutes of work? Then we go deeper.
Step 3: The 15+ Minute Fix - Registry Tweak for Windows Users
This one is for Windows only. It's a bit invasive, but I've seen it permanently squash error 12 on machines that do heavy 4K work. The problem is sometimes AE's memory allocation gets capped by a stale registry entry from an old install.
Back up your registry first. I mean it. Export the key we're about to touch.
- Close After Effects completely.
- Press Win + R, type
regedit, and hit Enter. - Go to this path:
HKEY_CURRENT_USER\Software\Adobe\After Effects\You'll see a subkey that looks like 18.0 (or whatever version you're on). Under that, find the Memory key. If it doesn't exist, right-click in the right pane and create a new DWORD (32-bit) Value called ReservedMemory.
Set its value to 2048 (decimal). That's 2 GB reserved for other apps. If you've already set this in Preferences, this just makes it stick.
Also look for a DWORD called RAMCacheSize. If it's set to something tiny like 100, bump it to 1024 (1 GB) or higher. That's the disk cache size in MB. A small cache makes AE thrash and trigger memory errors.
Restart your PC. When AE starts, check that the Preferences show the reserved RAM you set. If you ever see the error again, purge memory first—it's your fastest friend.
When to Skip This Entire Article
If you've gone through all three steps and still hit the wall, check your actual system RAM. Open Task Manager (Ctrl+Shift+Esc) and look at Memory. If your total RAM is 8 GB or less, you're fighting physics. AE needs a minimum of 16 GB to be comfortable, and 32 GB is where it stops complaining. The only real fix there is a RAM upgrade.
One More Thing That's Not Memory
I've seen error 12 appear on a Mac when the disk is completely full. AE uses a disk cache, and if there's no room to write, it tries to load everything into RAM and fails. Check your free disk space. If you're under 10 GB free, clear some room and try again.
Now go render. And if this article saved you, pass it to the next person who's crying over error 12.