Can't open certain Sonic 06 files

I've been trying to extract certain files from Sonic 06, but I can't open some of the files, usually giving me this error. 

<img width="2748" height="1230" alt="Image" src="https://github.com/user-attachments/assets/67d6dc18-6881-4c98-8443-7dcdcba11091" /> 

I'm not entirely sure if I'm just doing it wrong, but files like "fmef_Root" usually give this error. 