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

A script UI panel loading on startup is faulty. 5 Ways to Fix "Asked to Create Unknown Property of Type"

If the error loops continuously and prevents you from opening your .aep project file entirely, bypass the corruption by starting fresh: Launch with a blank, empty project. Navigate to File > Import > File . Select your corrupted or broken .aep file and click Import .

Complex dropdown combinations confuse the properties hierarchy. Simplify structure using time-remapping workflows. System memory reads outdated layout definitions. Purge memory or clear user preference configurations. 💡 Best Practices to Avoid Property Conflicts asked to create unknown property of type - Adobe Community

To prevent this in the future, a "Property Resolver" feature could be proposed to Adobe: A script UI panel loading on startup is faulty

: If the error is expression-related, try switching engines. Go to File > Project Settings > Expressions and change the engine to Legacy ExtendScript .

Alt-Click (Windows) or Option-Click (Mac) the stopwatch icon to disable the expression. 5. Update or Re-path Expressions

If a specific project file won't open, importing it into a fresh project can bypass corrupted startup metadata. Select your corrupted or broken

Navigate to the folder (typically found in Support Files/Scripts/ScriptUI Panels on Windows or Applications/Adobe After Effects/Scripts/ScriptUI Panels on macOS).

Opening a project that uses effects from plugins you don't have installed (e.g., Boris FX BCC, Red Giant Universe). Pseudo-Effects & Presets:

: Giving an effect parameter an internal system name like Layer , Camera , or Light causes an initialization loop. System memory reads outdated layout definitions

Bad metadata inside your custom presets folder can force After Effects to look for properties that do not exist. asked to create unknown property of type - Adobe Community

If you’ve been working in Adobe After Effects long enough, you’ve probably seen a few head-scratching error codes. But the one that has been popping up more frequently lately—especially for users working with expressions, templates, or specific third-party scripts—is:

If none of the above solutions work, you can try some advanced troubleshooting techniques:

Ensure that any third-party plugins or effect presets you're using are compatible with your version of After Effects.