Hi everyone,

I recently updated to MacOS Tahoe,
Since then I encountered several issues with Chimera, ChmieraX and python.
I installed and removed and reinstalled the apps but I still get the same error.

For chimera I get this error:

Screenshot 2025-09-24 at 12.08.51 AM.png
FOr ChimeraX, when I try to open a session, it complains that the session was created with another version of python. I opened that session successfully several times before to the update of MacOS and I have never seen this error before.

Failed opening file /Users/x/x/x/x/x/x/x/x.pyc:
Python code was compiled for a different version of Python


Can you please help me fix this?

Best Regards,
Othman 


Dr. Othman Rechiche
Herbert Irving Comprehensive Cancer Center
Columbia University Medical Center
Columbia University
New York, NY 10032
email: or2296@cumc.columbia.edu  
phone: +1 (814) 880-5554