Adobe After Effects — Cached Preview Error — What It Means & How to Fix It

What Does This Error Mean?

After Effects uses a preview cache to pre-render frames so you can watch your animation in real time. A cached preview error usually means the cache files have become corrupted, the drive storing them is full, or After Effects cannot access the folder where it saves them. Clearing the cache is the fastest fix — it forces After Effects to start fresh. You will need to wait for it to re-render the preview, but the error will go away.

Affected Models

Adobe After Effects CC 2020
Adobe After Effects CC 2021
Adobe After Effects CC 2022
Adobe After Effects CC 2023
Adobe After Effects CC 2024

Common Causes

The disk where the preview cache is stored has run out of space
Cached preview files were corrupted by a crash or power cut during rendering
The cache folder has been moved, renamed, or deleted since After Effects last saved cache files there
After Effects ran out of RAM mid-preview and created an incomplete cache
A mismatch between the project frame rate and the cached preview frame rate

How to Fix It

Clear the disk cache. Go to Edit > Purge > All Memory & Disk Cache. Click OK to confirm. After Effects will delete all cached frames and start fresh. This fixes corrupted cache files immediately.

Purging the cache does not delete your project — only the temporary preview files. Your work is safe.
Check how much disk space is available on the drive storing your cache. Go to Edit > Preferences > Media & Disk Cache. Look at the Maximum Disk Cache Size setting and check whether the drive actually has that much space free.

After Effects needs the full amount of cache space available. If your drive does not have enough free space, reduce the maximum cache size or point the cache to a different drive.
Move the cache to a different location. In Edit > Preferences > Media & Disk Cache, click Choose Folder and select a drive with plenty of space — ideally a fast SSD with at least 50 GB free. Click OK and restart After Effects.

Storing the cache on your fastest available SSD dramatically improves preview performance as well as preventing space-related errors.
Check your composition settings match your footage. Go to Composition > Composition Settings and make sure the frame rate, resolution, and duration match what your footage actually is. A mismatch can cause After Effects to struggle to cache correctly.

A common mistake is dropping 60fps footage into a 24fps comp — After Effects has to interpret the frames, which can create cache inconsistencies.
Reduce the preview resolution. In the Composition panel at the bottom, find the Resolution/Down Sample Factor dropdown (it may say Full, Half, or Third). Switch from Full to Half or Third. This renders previews at a lower resolution and uses far less memory and disk space.

Half resolution previews look slightly less sharp but play back much faster and create far fewer cache errors. For final output you always render at full quality anyway.

When to Call a Professional

Cached preview errors are a normal part of working with After Effects and do not indicate hardware failure. You can fix them yourself by following the steps below. If After Effects crashes repeatedly every time it tries to build a preview, your system may be underpowered for the complexity of your project. Consider splitting large compositions into smaller pre-comps, or upgrading your RAM and storage.

Frequently Asked Questions

Why does After Effects keep running out of preview cache so fast?

After Effects stores every single frame of your composition as an image file in the cache. At full resolution and 30fps, even a 60-second composition can generate several gigabytes of cache files. Complex compositions with 3D layers and effects generate even more. Increasing the maximum cache size or using a larger dedicated drive solves this.

I cleared the cache but the error keeps coming back. Why?

The most likely reason is that your drive keeps running out of space. Check how full the drive is where the cache is stored. If it is consistently getting full, either reduce the maximum cache size so After Effects stops before the drive runs out, or move the cache to a larger drive.

After Effects says 'cached preview needs 2 or more frames to play back'. What does that mean?

This means After Effects has not finished rendering enough frames to start playing a smooth preview. Press the spacebar or click the RAM Preview button and wait for the green bar to build across the timeline before pressing play. If the green bar fills very slowly, lower the preview resolution to Half or Third — this speeds up the caching process significantly.