After Effects Error Asked To Create Unknown Property Of Type Fix [cracked] Jun 2026

Corrupted preferences can cause a variety of issues.

Go to , or press Ctrl + I ( Cmd + I on Mac).

If the project uses expressions from older versions of After Effects, the engine may struggle to read them. Go to File > Scripts > Update Legacy Expressions.jsx to automatically update them to the modern engine. Remove Conflicting Scripts:

Look for the layer with an expression error (the stopwatch icon will turn red). Corrupted preferences can cause a variety of issues

Select . This often resets the internal property referencing. 3. Check for Missing Plugins/Effects

If you can tell me if the error happens upon opening the app or only opening a specific project , I can provide more targeted steps. asked to create unknown property of type - Adobe Community

folder (located in your Adobe After Effects installation directory) and re-add them one by one to find the "troublemaker". Check Plugins Go to File > Scripts > Update Legacy Expressions

Are you experiencing the frustrating "After Effects error asked to create unknown property of type" error while working on your project? This error can be a major roadblock, especially when you're on a deadline. In this article, we'll explore the causes of this error, its symptoms, and most importantly, provide a step-by-step guide on how to fix it.

For project-open errors, try creating a new file and importing the problematic one.

: Ensure any third-party plugins (like Red Giant , Boris FX , or Video Copilot ) used in the project are actually installed . This often resets the internal property referencing

If the error message includes a specific property name (e.g., "unknown property of type 'Mask Feather'"), use that clue to inspect your project for that specific property. Deleting and re-creating that specific property (e.g., removing a mask and drawing a new one) often resolves the issue immediately.

Now for the part you're really here for. Below is a series of troubleshooting steps, starting with the least invasive and moving to more involved solutions.

Ensure your strings strictly utilize updated documentation rules. For instance, creating a shape repeater requires a valid match name mapping under the shape group contents. Double-check capitalization and hyphens against an up-to-date Adobe ExtendScript dictionary. Quick Reference: Troubleshooting Summary Primary Cause Immediate Solution Loading older .aep templates Outdated coding strings Run Appears immediately on startup Broken ScriptUI layout file Clear out the ScriptUI Panels directory Project won't open at all Structural composition lock Import file into a blank project Using specific third-party presets Missing layout sliders/effects Update or reinstall the target Plug-in