The "asked to create unknown property of type" error in Adobe After Effects typically occurs when the software encounters a missing plugin, an incompatible preset, or a bugged script that references a property After Effects doesn't recognize Common Causes Missing Third-Party Plugins: Opening a project that uses effects from plugins you don't have installed (e.g., Boris FX BCC, Red Giant Universe). Pseudo-Effects & Presets: Applying a preset that relies on a "pseudo-effect" (custom-coded controls) that hasn't been properly initialised or created in your version of After Effects. Legacy Expressions: Using older project files or templates with expressions built for older versions of the After Effects Javascript engine. Essential Graphics/Master Properties: A known bug where using dropdown menu controls in master properties can trigger this error during startup. How to Fix Error: asked to created unknown property of type "x" (1d16) 21 Jun 2022 —
This error message, "After Effects error: asked to create unknown property of type...," is one of the most cryptic and frustrating crashes in After Effects. It essentially means the software tried to generate a parameter (like a position keyframe, a mask, or an effect controller) but the internal "blueprint" for that parameter was missing or corrupted. Because this error is triggered by different underlying causes, there is no single "fix." Instead, you have to systematically rule out the common culprits. Here is a deep dive into why this happens and how to fix it.
1. The Most Common Culprit: Corrupt "Mocha" Data If this error happens when you open a project, move the time indicator, or try to render, it is often caused by embedded Mocha data inside a layer. The Scenario: You applied a Mocha Pro plugin (or used the built-in Mocha tracking workflow) and the data embedded in the layer has become corrupt. AE tries to read the tracking data property but fails to identify what type of data it is. The Fix:
Select the layer causing the crash (you may need to open the project in a new copy to identify it). If you have Mocha Pro installed, apply the effect, open the Mocha interface, and click "Remove Data" or reset the effect. If you do not have Mocha installed, you can try to remove the tracking data manually: The "asked to create unknown property of type"
Select the layer. Go to Effect Controls . If you see a Mocha effect, delete it.
The "Secret" Fix: Sometimes the data isn't visible.
Select the problem layer. Go to the menu: Layer > Mask and Shape Path > Roto Brush & Refine Edge > Freeze . (This forces AE to recalculate internal properties). Alternatively, if you suspect a specific third-party plugin (like Mocha), try deleting that specific effect instance. Because this error is triggered by different underlying
2. The Third-Party Plugin Conflict (The "Type" Clue) If the error message includes a specific keyword after "type" (e.g., "type Pseudo/Effect Name"), it points directly to a plugin. The Scenario: You are using a plugin (like Red Giant Trapcode, Video Copilot Element 3D, or a script like Duik Bassel). The plugin creates "Pseudo Effects" (custom user interfaces). If the plugin version mismatches the project version, or the plugin is missing, AE cannot create the UI property. The Fix:
Identify the Plugin: Look closely at the error message. Does it say Pseudo/VC_E3D ? That's Element 3D. Does it say Pseudo/Duik ? That's Duik. Update the Plugin: Ensure you have the exact version of the plugin used to create the project installed on your machine. Disable Plugins: If you cannot find the plugin, try launching AE while holding Shift + Alt / Option . This opens the Preferences dialog and allows you to disable third-party plugins temporarily so you can open the project and delete the offending layer/effect.
3. Corrupt Expressions Linking Missing Properties The Scenario: You have an expression (the little pick-whip code) linking one property to another. Sometimes, if the source property is deleted or renamed, the expression tries to "create" a link to a property that no longer exists, confusing AE. The Fix: creating a "
Open the project. If you can access the timeline, press U to reveal all keyframes. Look for expression errors (usually shown as a warning icon next to the expression). Delete the expression or use the command: Expression Tools > Delete All Expressions (if you have a script for it). If the project crashes immediately upon opening, try importing the project into a New Project (File > Import > Project) rather than opening it directly.
4. The Essential Graphics Panel Bug The Scenario: You created a Motion Graphics Template (MOGRT) or used the Essential Graphics panel. Sometimes, creating a "Master Property" and then deleting the underlying source (like a shape layer) causes this "unknown property" error because AE is still trying to create the Master Property link. The Fix: