Download the exact plugin version required by the original file creator.
As the deadline drew closer, Alex became more and more desperate. They searched online for solutions, but every forum post and tutorial they found seemed to suggest a different fix. Some people suggested deleting the plugin, while others recommended resetting the After Effects preferences.
Navigate to your local Adobe system script folder: Program Files\Adobe\Adobe After Effects [Version]\Support Files\Scripts\ScriptUI Panels Move third-party scripts temporarily out of this folder.
Relaunch the program to check if the error prompt stops repeating. 3. Update Legacy Expression Code
Expressions cannot create new properties permanently. If you're trying to write a custom value into a non‑existent property, AE will throw this error.
var myLayer = app.project.activeItem.layer(1); var myProp = myLayer.property("transform").property("position"); if (myProp != null) myProp.setValue([100, 200]); else alert("Position property not found");
Older animation presets often contain obsolete expression methods that the modern JavaScript rendering engine cannot decipher. asked to create unknown property of type | Community
"ADBE Mask" , "ADBE Effect" , "ADBE Paint" , etc. Wrong: passing a custom string that AE doesn't recognize.