CVX can not solve the optimal reveals 'NaN'

The code did not report an error,but the optimal value could not be solved.So what causes the result? Maybe it rerlates to the initial value?

Reproducible code and log output from the solver please.

Sorry,I did not get it.

I meant it is impossible to answer in such generality and you should provide your code and at least show log output from the solver(s) to get meaningful help.