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

Restart After Effects. If the error is gone, move the scripts back one by one to identify the culprit. 4. Re-install/Update the Template/Preset

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:

Corrupted preferences can cause a variety of issues. Restart After Effects

The error frequently appears in a few contexts:

For deeper diagnostics, run the application in a sandboxed state to confirm whether hardware conflicts are compounding the issue. Navigate to . The error frequently appears in a few contexts:

If the error started appearing after you imported a project from a different computer or an online source, reach out to the creator. They may know exactly what third-party effect, script, or step is required for the error not to occur.

: Custom sliders or control panels embedded in downloaded templates that use obsolete naming conventions. especially if they are variable fonts.

or reinstall third-party fonts used in the project, especially if they are variable fonts. Reset Preferences: Launch After Effects while holding Ctrl+Alt+Shift (Windows) or Command+Option+Shift (Mac) to delete the preferences file. Import into a New Project: Create a brand new file and use File > Import > File

, simply closing the extension panel and reopening it can reset the "boot" process and clear the error. Identification Tip