Quick fixes: After Effects preview not working

After Effects 10/06/2021 5 min read
After Effects Cached Preview Error

If you’re familiar with After Effects, you’ve probably encountered the dreaded disk cache error message. If you’re unsure what it means, it’s easy to click past and continue your work, but previewing it later will be challenging. Luckily, Motion Array has 10 quick fixes for After Effects previews not working to get you back to editing without issues.

Part 1: 10 smart fixes for After Effects not caching the preview

When you preview your work in After Effects, the software creates render files. These files are saved to your hard drive and need a share of the RAM available. If After Effects previews aren’t working, this error lets you know that it doesn’t have enough space to render your project. The lack of space can result in a low-quality playback and, in some cases, no preview at all.

The solutions are more in-depth if you’re using 3D cameras in your project or a third-party plugin such as Element 3D. But first, go through Motion Array’s list of 10 quick fixes — you’re sure to find an easy solution.

1. Purge the RAM cache

Your RAM cache is where After Effects saves the rendered preview files for your projects. While these files aren’t massive on their own, they can quickly build up and cause issues. To purge the cache, go to Edit > Purge > All Memory. This will clear all the cache files saved to your machine’s RAM.

2. Empty the disk cache

After Effects saves cache files to both your RAM and your hard drive. If you’ve cleared your RAM and still find After Effects isn’t caching the preview, it’s also worth emptying your disk cache. This handy function is located just above the RAM option: Edit > Purge > All Memory and Disk Cache.

3. Close unused programs

Close all other applications to prevent programs from competing for system memory. This can be annoying when working between After Effects, Adobe Premiere Pro, and Adobe Illustrator, but pushing your system too hard can cause ongoing memory issues. Where there’s low memory, After Effects previews not working correctly will inevitably follow.

4. Increase the RAM

If you do need to have multiple programs open at the same time, Adobe will let you set how much RAM each one can use. Go to Preferences > Memory to view the RAM allocated to Adobe, and drag the RAM number as high as it will go. You can change this later if you need more RAM for other programs. This is a great fix when preview playback is choppy, but not non-existent.

5. Change the disk cache location

This is another thing that can cause After Effects to not cache the preview, but only some editors know about changing the disk cache location. The software will struggle to read and write files to the same location except on high-power devices.

For the best workflow, you should have a separate storage solution for your project files and your cache files. Most After Effects users create projects on an external drive, while the cache files are saved to the local drive.

To change the disk cache location, go to After Effects > Preferences > Media and Disk Cache, and select Choose Folder under Disk Cache.

6. Clean the database and cache

You can also clean the media database and cache in the Preferences menu, however, this method will only delete files where the source file is unavailable. Still, this is an excellent option for archiving an old project with its render files.

Go to After Effects > Preferences > Media and Disk Cache and choose Clean Database and Cache.

7. Organize and simplify your project

You can organize and simplify your projects in several ways to make After Effects render your work more efficiently. After Effects struggles with resources when there are too many pre-comps within pre-comps or nested sequences, so check how your project is structured and see if you can simplify it. If it’s a big project, try dividing it into smaller chunks and work on it in sections.

You should also check your pre-comp sizing. When importing graphics, you can quickly end up with huge compositions. These large comps will be scaled down, but After Effects must still read the big pre-comp file. Proxy files can help a lot, too.

You can also simplify your project by removing unused footage or imported files. This is usually done once a project is finished and you want to archive it, but it can also help speed up your system while you work. Go to File > Dependencies > Remove Unused Footage.

A final option for simplifying your project is to optimize your effects. Some effects in After Effects can be pretty difficult to render, so try turning off your effects to see if the playback improves. If you can, move your effects to adjustment layers that can be switched on and off easily.

8. Set your region of interest and work area

Minimizing your area of interest and work can help After Effects create quicker render files by focusing on a smaller portion of your composition. 

To change your work area, drag the In and Out points of your timeline to view only the portion you want to preview. You can also place your playhead on the timeline, and use the B and N keys to create In and Out points.

To set your region of interest, choose the Region icon from the bottom of the viewer and draw a box on your screen covering the area you want to view. Once you’ve watched your preview, uncheck the Region icon to go back to full view.

9. Re-import your rendered clips

Re-importing your rendered clips should be your last choice, as it can create a challenging workflow. Essentially, you’ll render out portions of your video and re-import them as video files.

Exporting and importing sections of your project can be incredibly helpful when you have a clear workflow. For example, you could render video footage with heavy effects and re-import them as clips for a motion graphics frame. However, if you need to go back and change elements later, it can create a complex workflow.

10. Optimize your machine

If you’ve tried these methods and are still getting the preview error message, it might be time to examine your device. If you recently updated your software or operating system, there may be conflicts causing the issue. Adobe has all the system specs for After Effects available on its website.

Part 2: 3 additional tips to avoid slow previews in After Effects

If you’re not getting the After Effects preview error, but your playback is still struggling, you can try a few things to preview your work better.

1. Skip frames

After Effects lets you choose the frame rate at which you preview your composition without changing the project frame rate. You can also choose to skip frames, which can help After Effects smooth the look of your preview.

  1. To open the Preview settings, go to Window > Preview
  2. In the Preview panel, choose your preferred Preview Frame Rate.
  3. Choose to skip every 2 frames.

2. Change preview quality

If you want to preview the speed and flow of your animation, but aren’t too worried about seeing it in HD, you can change the preview quality. For example, changing your playback to half the quality will result in much smaller render files. This can help to reduce the chances of After Effects not caching the preview.

3. Speed up rendering

You can also check a couple of boxes to help After Effects speed up the rendering process.

  1. Go to After Effects > Preferences. Hold Shift and click General.
  2. In the left-hand column, select Secret.
  3. Select Disable Layer Cache and Ignore Sequence Rendering Errors.
  4. Under Purge Every, adjust the number of frames to 2.

As you can see, preview errors are common in animation work. Ensuring your machine is kept organized and well-maintained will go a long way to prevent After Effects preview errors in the first place. Hopefully one of Motion Array’s tips has fixed your After Effects preview error. If you still have problems rendering your projects, check out these 5 troubleshooting tricks.