It seems to me this problem is closely related to MATLAB nargchk deprecated. The reason is that there is a file narginchk.m in lib\narginchk_ in CVX defining the respective function that duplicates a built-in one within Matlab. If you include this narginchk.m from CVX in your paths, it shadows the built-one Matlab function with the same name. And the problems occurs when Matlab starts because its initialization narginchk is used and in this case CVX narginchk is called instead of the built-in one. And this leads somehow to improper functioning of Java after this.
My advice is to remove the whole subfolder narginchk_ from lib folder. Or at least to follow this http://ask.cvxr.com/t/matlab-nargchk-deprecated/3380/15. I do not understand why it was necessary to duplicate this built-one function. It is not safe at all…