This Bugzilla instance is a read-only archive of historic NetBeans bug reports. To report a bug in NetBeans please follow the project's instructions for reporting issues.
If a new composite component is created using NetBeans IDE and this component is used in a different page then the corresponding namespace URI needs to be explicitly declared in the top-level element. It'd be great if the IDE can offer hint to resolve the namespace URI.
This old bug may not be relevant anymore. If you can still reproduce it in 8.2 development builds please reopen this issue. Thanks for your cooperation, NetBeans IDE 8.2 Release Boss