Model.quadcon must be a struct array with fields q, and rhs error in CVX

This is my first time to use CVX, and I want to see how it works with a simple example. The following is the example that I am trying:
% Matlab code
variable x(1)
minimize( x(1) )
subject to

However, I got the error ‘model.quadcon must be a struct array with fields q, and rhs’. Does my example itself have some issues, and is there any way to fix this issue? Thanks!

This should run and produce an optimal solution. if it doesn’t, then either you are using a buggy version of CVX, such as 3.0beta, in which case please switch to CV X2.2, or something is screwed up in your CVX installation.

The output of
shows whixh CVX version you are using.