EnvironmentNotWritableError: The current user does not have write permissions to the target environment.
environment location: C:\ProgramData\Anaconda3
This does not appear to be a CVX issue. You mention mosek and Anaconda, so help forums for one of those two would seem appropriate. Even if your intention is to install mosek for use in CVX, that requires installation of mosek in MATLAB, whereas, as far as i know, Anaconda packaging of mosek only pertains to Python, not MATLAB.