Ensure your computer meets the minimum system requirements for After Effects. Also, make sure your graphics drivers are up to date, as outdated drivers can cause issues.
If you are a motion designer, video editor, or visual effects artist, you have likely encountered the dreaded cryptic red warning box in Adobe After Effects. Among the most frustrating and confusing of these is the error:
"After Effects: Asked to create unknown property of type 'fix'." Ensure your computer meets the minimum system requirements
This error typically brings your workflow to a screeching halt, preventing you from saving, rendering, or even closing the application without a force quit. Unlike a simple syntax error, the "fix" property error points to deeper corruption, plugin conflicts, or project file damage.
In this comprehensive 2,500+ word guide, we will break down exactly what triggers this error, why Adobe engineers named it "fix," and, most importantly, provide a step-by-step roadmap to resolve it permanently. If the error message includes a specific keyword
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. Before reopening After Effects after encountering the error,
The Fix:
Prevention beats cure. Adopt these habits to never see "asked to create unknown property of type 'fix'" again.
| Prevention Tactic | Why It Works |
|------------------|---------------|
| Save as .aepx (XML-based) | XML files are human-readable and recoverable. Go to Preferences > Files and enable "Allow script to write files and network." |
| Use an Auto-Save interval of 10 minutes | Limits data loss. Set via Edit > Preferences > Auto-Save. |
| Avoid nested effects from different vendors | Mixing Boris FX with Red Giant on the same layer increases property type conflicts. |
| Collapse transformations sparingly | The "fix" error often triggers when a pre-comp with collapse transformations contains a 3D layer with a corrupt effect. |
| Update plugins before updating AE | Always update Trapcode, Sapphire, and Element 3D before upgrading your AE version. |
| Run the Built-in Project Fixer | Go to File > Scripts > Project Fixer (after installing the free script from Adobe Community). |
Before reopening After Effects after encountering the error, run through this checklist: