Quickly Fix Preview Not Working (Slow) Errors in After Effects

After Effects 12/05/2021 4 min read

The After Effects preview is a temperamental thing. The preview not working is one of the most frustrating problems you will come across when in the middle of a project. You’ll also probably recognize the error message “After Effects error: Cached preview needs two or more frames to playback.”

There’s nothing worse than having your workflow interrupted by your After Effects preview not working, particularly when you’re on a tight deadline. But don’t worry, there are a few ways you can troubleshoot your preview errors to get your project back up again. Let’s run through them.

Part 1: Preview Won’t Play Error in After Effects

If you’re having trouble with previewing your project in After Effects, things can really slow down. Try running through this process, a slightly more advanced version of the tried and tested ‘turn it off and on again’.

  1. End the After Effects task by going through the Task Manager, or Force Quit the Application (Cmd + Opt + Esc). This will close After Effects so it’s no longer affecting your computer’s memory and CPU.
  2. In the Finder, go to your Adobe software folder and select the After Effects subfolder.
  3. Change the name of the After Effects folder by adding “.old” to the end.
  4. If you’re on a PC, you can try the same thing. Go to Users > Admin > App Data > Running, then in the Adobe folder and rename the After Effects folder After Effects.old.

Part 2: Cached Preview Error in After Effects

If you encounter the error message Cached Preview Needs 2 or More Frames to Playback, it’s worth understanding a bit about how After Effects works.

To play the video previews in your project, After Effects creates temporary video files on your computer known as cache files. After Effects works most effectively on computers with large amounts of RAM because these RAM cache files require a decent amount of space to operate. If your computer has less than 8GB of RAM you may find there is not enough room on your RAM to load larger temporary video files.

So what can you do if the After Effects preview is not working? Try the following troubleshooting steps.

1. Purge the RAM cache.

Purging the RAM cache removes all the temporary video files on your computer, giving it the opportunity to start again. It’s a good place to start if your computer does not have a lot of RAM. To do this, go to Edit > Purge > All Memory.

2. Empty Disk Cache

The Disk Cache is a store of preview files based on your hard drive, rather than your RAM, allowing After Effects to view and use them much quicker. To empty this, go to Preferences > Media and Disk Cache > Empty Disk Cache.

3. Clean Database & Cache

While you’re in the same window to Empty Disk Cache, try cleaning the database and the cache by hitting Clean Database and Cache.

4. Change Disk Cache Location

Having the disk cache on your computer can slow it down as it will be doing multiple things at once, so try moving your disk cache onto another hard drive like an external SSD. To do this, go to After Effects  > Preferences > Media and Disk Cache. Select Choose Folder under Disk Cache and then choose a new folder on a different hard drive.

5. End Task of Other Applications

If your computer is trying to do multiple things at the same time, end other tasks to focus purely on After Effects. Close applications like browsers, Spotify, iTunes, and even Premiere Pro if you don’t need it.

6. Organize Your Project

Is your project a huge web of precomps and effects? Sometimes the sheer volume of assets you’re working with can be enough to slow a project down. Try organizing your project by removing any unused assets, layers, and simplifying your precomps.

7. Optimize Your Effects

Effects are heavy on a project, and some are heavier than others. Blur effects, stabilizers, color corrections all require processing power which can significantly slow down your project and affect your preview playback. Go through all your effects and remove any that aren’t necessary. If they are, try optimizing them by replacing them with a different type, for example, the lens blur effect with the fast box blur effect.

8. Adjust Preview Quality

There are two types of preview resolutions in After Effects – pause and play resolution. The pause resolution is controlled by the video resolution drop down under your composition window. While the play resolution is controlled by the resolution control in your preview panel. You can easily adjust the video resolution any time you play or preview your animation.

9. Update the Graphics Card Driver

Keeping the drivers updated helps fix bugs in your system and keeps it compatible with more recent software. It might be the case that if you’re working on an older computer, After Effects is conflicting with your graphics card. Updating the graphics card driver could help to iron out any problems and make your whole After Effects operation smoother.

After Effects can be a demanding software that requires a lot of complex processes all at once. The After Effects preview not working can be a common problem, and a frustrating one, but there’s a lot you can do to troubleshoot it. Some of the main steps include cleaning the cache, organizing and optimizing your project, and keep your system updated to stay on top of any known issues.

If you’re having trouble with playing back audio in After Effects, check out our troubleshooting tutorial here. If you run into problems rendering, we also have this handy rendering troubleshooting tutorial.