When adding Apache Tomcat 8 to NetBeans 7.3.1, an error will occur saying the specified server location catalina home folder is not valid. This is because Tomcat 8 is not compatible with NetBeans 7.3.1. To use tomcat 8, download NetBeans 8 from Oracle and add the tomcat server. NetBeans 8 and Tomcat 8 are compatible.