This error usually happens when After Effects tries to load a , script, or preset that it doesn't recognize or that was created for a different version . It’s common when using older templates or third-party plugins like Red Giant Universe .
After Effects is trying to generate a property (like a slider or checkbox) but encounters a data type it does not recognize. Instead of crashing immediately, it throws the "unknown property of type 'fix'" error, often getting stuck in an infinite loop. This error usually happens when After Effects tries
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. Instead of crashing immediately, it throws the "unknown
If you are the one creating the preset, ensure that the names in your pseudo-effect do not conflict with After Effects' internal naming structure (e.g., avoid using general terms like "Layer" as a custom property name). Instead of crashing immediately
: /Applications/Adobe After Effects (version)/Scripts/ScriptUI Panels . The "Isolation" Method : Close After Effects.
General corruption can lead to "unknown BIB" or property errors.