Create Unknown Property Of Type Fix _top_ — After Effects Error Asked To

You must identify and isolate the specific script causing the initialization failure. Close the application completely. Navigate to your local installation directory:

After Effects will treat the old project structure as an asset folder, allowing you to salvage your individual compositions without activating the bugged sequence on startup. Diagnostic Check Checklist asked to create unknown property of type - Adobe Community

The error is almost always an issue with an expression trying to call a property that cannot be found. By identifying the broken layer, cleaning up the expression, or pre-composing, you can usually resolve this issue quickly.

If the warning box locks your interface or loops infinitely, preventing you from navigating your timeline, bypass it through a fresh workspace asset import. Launch a completely blank, new After Effects project. Choose (or hit Ctrl + I / Cmd + I ). You must identify and isolate the specific script

This error is frequently linked to specific third-party tools like or custom Master Properties/Dropdown Controls .

If the file is corrupted at the structural level (XML data corruption), you need to strip the metadata.

If the error occurs after you manually drag and drop a preset ( .ffx ), the script file itself is likely poorly coded or formatted for an older version of the software: Close After Effects. Navigate to your directory: Diagnostic Check Checklist asked to create unknown property

This error typically arises from a disconnect between what a piece of code (expression or script) is asking for and what the After Effects project actually contains. Common scenarios include:

If the project file itself is corrupted or stuck in a loop, importing it as a piece of footage into a fresh project can bypass the launch error.

Here is a deep dive into why this happens and how to fix it. Launch a completely blank, new After Effects project

: Opening an older project file or Envato/Motion Array template that relies on custom "pseudo-effects" (custom slider controls embedded in a layer) which are missing on your machine or built for a legacy After Effects version.

Let the automated script run to update the older expressions to the modern JavaScript engine. 3. Clear User Presets and Third-Party Scripts

If the error message includes a specific keyword after "type" (e.g., "type Pseudo/Effect Name"), it points directly to a plugin.

Remove scripts one by one to identify which one causes the error.