This bug was originally marked as duplicate of bug 186523, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.

Build: NetBeans IDE 6.9.1 (Build 201007282301)
VM: Java HotSpot(TM) Client VM, 17.0-b17, Java(TM) SE Runtime Environment, 1.6.0_21-b07
OS: Windows 7

User Comments:
GUEST: Attempting to debug a locally running maven build.

wklaczynski: Debug with jboss on fedora 11, previous wersion netbeans works fine.

GUEST: just tried remote debugging.

GUEST: attaching debugger

Sveromm: I have last version of NetBeans...

GUEST: Trying to connect to the server

GUEST: Was trying to attach debugger at Jboss 5.1.0GA (default server listening for debug request at port 8686)

GUEST: Trying to attach debugger

GUEST: Attaching a debugger on jboss

GUEST: build 20100610 - bug still exist

averri: Debugging a web application deployed on Tomcat. The Tomcat was started with: catalina.bat jpda start

GUEST: attaching debbuger to server

GUEST: Attempting to attach debugger to a JVM.

GUEST: Trying to attach to a local glassfish...

GUEST: When trying to attach debuger to jetty/weblogic server.

pekarna: Tried to attach a debugger to a Maven project started using `mvnDebug test -Dtest=*Fakt*`

GUEST: Attaching debugger fails with an exception. The stacktrace mentions a source jar in my repository. Upon deleting this, and any other source jars that cause exceptions on subsequent tries, I am able to attach.

GUEST: attached debugger through socket

GUEST: Attach the debugger to a jvm running on the same maching and listening on port 10011

jfeid: Started Tomcat 6 in debug mode from Services window and then Debug -> Attach Debugger

GUEST: attaching debugger to tomcat instance not registered within netbeans, using JPDA SharedMemoryAttach.

GUEST: When I try to connect my debugger to a running java process (remote debugging) I get the following error

Sveromm: Cannot attach jpda debugger!

mpiffret: Attaching a debugger to jboss 5.1.0GA jdk6 on MacOS 10.6.3 using latest java update.

GUEST: trying to attach the debugger

GUEST: Remote debug on jboss on port 8787




Stacktrace: 
java.lang.NullPointerException
   at org.netbeans.api.debugger.ActionsManager.registerActionsProviders(ActionsManager.java:428)
   at org.netbeans.api.debugger.ActionsManager.initActionImpls(ActionsManager.java:446)
   at org.netbeans.api.debugger.ActionsManager.isEnabled(ActionsManager.java:260)
   at org.netbeans.modules.debugger.ui.actions.DebuggerAction.isEnabled(DebuggerAction.java:127)
   at org.netbeans.modules.debugger.ui.actions.DebuggerAction.access$000(DebuggerAction.java:73)
   at org.netbeans.modules.debugger.ui.actions.DebuggerAction$Listener.propertyChange(DebuggerAction.java:374)