After Effects Error Asked To Create Unknown Property - Of Type Fix

This error usually prevents the action from completing and may sometimes cause the application to become unstable or crash.

How to Fix the "After Effects Error: Asked to Create Unknown Property of Type"

Remove scripts one by one to identify which one causes the error. This error usually prevents the action from completing

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

If you are building your own tools or using custom controllers, generic property naming conventions are likely breaking the project architecture. asked to create unknown property of type -

After Effects will pull the compositions into a folder, often rebuilding missing properties automatically. Save this as a new file. 2. Update Legacy Expressions

This error usually pops up when After Effects is trying to interpret a script, expression, or pseudo-effect (a custom controller) that it does not recognize or that has become corrupted. As of 2026, this often relates to bridging older project files with the latest, highly optimized AE expression engine. highly optimized AE expression engine.

The Adobe Support Community and forums are great resources. Someone else might have encountered the same issue and found a solution.