i just download magento 1.9.2.3 version. and i am unable to apply theme. i also have 1.8.0.0 version and it is working fine. but am getting problem with 1.9.2.3 version. also am unable to install theme form magento connect manager.
In admin panel System > Configuration > Advanced > Developer > Log Settings. Here enabled the log files. And check whether their is an any error in the log files. It will helps you to reproduce the error.
