After Effects Error Asked To Create Unknown Property Of Type Fix Best Jun 2026

A buggy script in your "ScriptUI Panels" folder can cause this on startup.

If you are using an older template in a newer version of After Effects, Adobe's internal changes may cause conflicts. A buggy script in your "ScriptUI Panels" folder

To avoid and troubleshoot this error, follow these steps: A buggy script in your "ScriptUI Panels" folder

: This is often the quickest fix if you're using an older template. Go to File > Scripts > Update Legacy Expressions.jsx . A buggy script in your "ScriptUI Panels" folder