This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
I'm not familiar with how NetBeans run web apps, but have you tried running it in a standalone Tomcat server? Then you could check the log files for what the actual problem is. I'd also guess that log messages are saved or displayed somewhere when run inside of NetBeans.