, simply closing the extension panel and reopening it can reset the "boot" process and clear the error. Identification Tip
This specific error is often triggered by or third-party scripts that attempt to initialize a user interface or background function using outdated or incorrect property identifiers. Because After Effects cannot identify what "type" of property the script is asking for, it halts the process. Primary Fix: Isolate and Remove Problematic Scripts
If the application displays an endless error loop before you can even view your timeline, corrupt global preferences are likely blocking standard composition initialization. , simply closing the extension panel and reopening
Code is trying to apply a 2D position property to a 3D layer, or vice versa, causing a type mismatch.
Given that plugins cause ~55% of "fix" errors, this method succeeds for most users. Primary Fix: Isolate and Remove Problematic Scripts If
to bring your old project into it. This can sometimes bypass project-level corruption. Change Expression Engine File > Project Settings > Expressions , try switching the "Expressions Engine" to Legacy ExtendScript Error: asked to created unknown property of type "x" (1d16)
Sometimes, an expression tries to create a keyframe where none can exist, or it tries to access a property that cannot exist. Ensure you are correctly accessing property values. Example: thisComp.layer("Layer").transform.opacity.value; Scenario C: Using Expression Controllers to bring your old project into it
Remember: every seasoned AE user has faced the "fix" error. It is a rite of passage. Fix it once, and you will never be slowed down by it again.
Relaunch After Effects. If the error is gone, one of those scripts was the "troublemaker".