the code provided on the lwjgl website doesn't work either. Same exception errors.
That is not possible. The code provided on the lwjgl.org/guide site does check for window==NULL. So it cannot be the same exception. Please be precise with your statements. Which _exact_ error are you getting for the example on the lwjgl.org/guide site and which _exact_ error output?
You also removed any checks and error logging in your code, so it is not possible to diagnose what could be the problem.
Also please start the JVM with the VM argument "-Dorg.lwjgl.util.Debug=true":
under Eclipse menu "Run" -> "Run Configurations..." -> choose your run configuration -> goto tab "Arguments" -> enter "-Dorg.lwjgl.util.Debug=true" into the field "VM arguments:" (without the quotes) and post the full and complete syserr/sysout output.