You should test your installation after installing to confirm everything works.
Navigate to:
/Users/<username>/Documents/MATLAB/cvx/<path to CVX>/examples
and run the file simple_LP.m in MATLAB.
...
Copy and paste the full-output into a text file and upload it to Stellar.
Some people have noticed that their default solver is Sdpt3 instead of SeDuMi. That's ok. Your installation is still working. We'll talk more about this in class.