Sometimes, After Effects tries to read from a corrupted cache file, leading to "Unknown Property" errors during preview or render. The Process Navigate to Edit > Purge > All Memory & Disk Cache. Click OK to confirm. Restart After Effects and try opening the project again. Step 4: Reset After Effects Preferences
Hold down Ctrl+Alt+Shift (Windows) or Command+Option+Shift (Mac) while launching the program. Sometimes, After Effects tries to read from a
After Effects will often "repair" the property links during the import process. Restart After Effects and try opening the project again
If the project uses a plugin you don't have installed, After Effects might struggle to define the properties associated with that plugin. How to Fix If the project uses a plugin you don't
If the project file itself is slightly corrupted, you can often bypass the error by importing it into a fresh workspace rather than opening it directly. Open After Effects and create a brand new project. Go to File > Import > File. Select the problematic .aep file.