UWS issues are quite rare.  It usually just works.  But every now and then we have an isolated case where it is not working right.  

Almost all of the issues that we have seen with the UWS are related to the Java installation.  Evidently, things can get confused in cases when there are multiple versions of the Java JRE installed.  

What works for most users is to uninstall all Java JRE and JDK software and reinstall the latest version of the JRE.  

You can download the latest version of the JRE HERE.