JSF (Oracle Mojarra 2.1.1): beware the exclamation mark!
It was one of those simple-but-nasty bugs that make you cry over them for several hours. The perfectly valid project just refused to start. I've got an error ( see the stacktrace below ): "com.sun.faces.config.ConfigurationException: CONFIGURATION FAILED! D:\ (The system cannot find the path specified)". I didn't know why on earth JSF wanted to read the configuration from the drive's root instead of using existing, perfectly legitimate configuration file until I started debugging the Mojarra's sources itself. Then it struck me - I put the project in the "D:\!eclipse\projectname" folder (note the exclamation mark!) and Mojarra just couldn't handle the exclamation mark because of the following code in the getAlternativeJarFile method of the com.sun.faces.facelets.util.Classpath :