Adobe Creative Cloud

favorite features in CC versions of After Effects: expression error handling

One of my favorite changes to After Effects recently isn’t a flashy feature at all, but it’s a change that has already saved me thousands of clicks when dealing with expression errors.

Beginning in After Effects CC 2015 (13.5), there are two major changes in what occurs when an expression fails to evaluate:

  • Expression errors appear in a warning banner at the bottom of the Composition and Layer panels instead of in a dialog box.
  • A failing expression is not disabled. The expression will continue to evaluate and will display the warning banner until the problem with the expression is fixed or manually disabled.

This means that when you have multiple expressions that fail, you no longer need to click through a potentially enormous number of error dialog boxes. Also, when you fix the cause of an expression’s failure, you no longer have to click to re-enable the expression. In some cases, fixing an expression may simply be a matter of undoing the change that caused the expression to fail.


On the right side of the expression error warning banner are control buttons:

  • The Left or Right arrow buttons display the previous or next expression error when multiple expressions fail to evaluate.
  • The Reveal Expression (magnifying glass) button will expose the property with the failing expression in the Timeline panel. If the expression is in a different composition, that composition will open.
  • The Expand Warning button increases the height of the warning banner to display the error text. Click the button again to reduce the height to a single row.
  • The expression error text is clipped to the width of the Composition panel. To see the full expression error in a dialog box, click on the yellow error triangle icon next to the expression in the Timeline panel.

The expression error text is one line only, and is clipped to the width of the Composition panel. To see the full expression error text in the old-style dialog box, click on the yellow error triangle icon next to the expression in the Timeline panel.

To hide the expression error warning banner, open Preferences > General and disable Show Warning Banner When Project Contains Expressions Errors. Note that when this option is disabled, the warning banner will not appear in After Effects, even when new expression errors occur. Re-enable this option to view expression errors.

Also worth mentioning in this context is a feature that is not new, but has existed in After Effects for many versions: the Reveal Expression Errors command, available the in the context menu when you right-click on a layer, will expose properties of the selected layers that have expressions that fail to evaluate.

Go ahead and try this out now in the current version. If you’re not already a Creative Cloud subscriber, you can try the free 30-day trial. For information about purchasing a Creative Cloud subscription, see this page about plans and this page with current promotional offers.

If you want to let us know what your favorite changes in After Effects have been since After Effects CC (12.0), come and tell us here, whether your favorite change is a new feature, a bug fix, or a little tweak in behavior.

After Effects, General, Region of Interest