Disciplined convex programming error1

How to solve this error:
Disciplined convex programming error:
Illegal operation: {log-concave} - {real constant}

We’re not mindreaders.

First question for you: have you proven the optimization model is convex? If it is, then reformulation is apparently required; but we ha no idea what that would be because we have no idea what your model is. It it’s not, then CVX can 't be used to solve the problem.