First,
you should not build your SelectItem list in the getItems() method. It's very inefficient and sometimes dangerous. For the most part,
JSF bean "set" and "get" methods should only do simple data access and the logic to construct or act on the data should be done somewhere else.
Most likely, the code inside getItems() is throwing an Exception for some reason. JSF has a very bad habit of throwing away details on such exceptions when they happen in property accessor methods. That is another reason why it's a good idea to build the backing data somewhere else.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.