If the error is caused by an old template, you can often fix it by converting the expressions to the modern engine: File > Scripts > Update Legacy Expressions.jsx Alternatively, go to File > Project Settings > Expressions and change the Expressions Engine to Legacy ExtendScript 2. Troubleshoot Scripts and Plugins Isolate Scripts : Remove scripts from the ScriptUI Panels
: /Applications/Adobe After Effects (version)/Scripts/ScriptUI Panels If the error is caused by an old
to bring your existing project into it. This often bypasses corrupted project settings. Are you seeing this error at startup or when clicking a specific layer in an existing project? asked to create unknown property of type - Adobe Community If the error is caused by an old