This bug was originally marked as duplicate of bug 234947, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.
Build: NetBeans IDE Dev (Build 201309250002)
VM: Java HotSpot(TM) 64-Bit Server VM, 23.25-b01, Java(TM) SE Runtime Environment, 1.7.0_25-b17
OS: Windows 7
Chiana: Tried to save a fxml file by pressing control-S
GUEST: Right click => Edit on an fxml file
Chiana: Pasted " xmlns:fx="http://javafx.com/fxml"" into a JavaFX "<AnchorPane" line
ionuion: right click on a fxml file in the project window
java.lang.NullPointerException: The description parameter cannot be null
Created attachment 140608 [details]
Created attachment 140609 [details]
Restarted IDE to get rid of this error, but it persists after restart...
This bug already has 5 duplicates
Created attachment 140610 [details]
Offending project (entire)
It seems this is related to the xmlns:fx="http://javafx.com/fxml/1" parameter that is set, that makes to not work properly, if you then add "xmlns:fx="http://javafx.com/fxml" this error occurs, if you on the other hand remove the "/1" from the xmlns:fx..." line it seems to work...
This exception likely a result of trying to redefine namespace xmlns:fx, e.g. xmlns:fx="http://javafx.com/fxml/1" xmlns:fx="http://javafx.com/javafx".
I copied that into my FXMLDocument.fxml and quickly received an Exception.
For the workaround, you should delete one of the xmlns:fx declarations - but bear in mind that each time you save the file in Scene Builder, it will update the namespaces as follows (using Scene Builder 1.1 GA, which correctly injects):
See also bug 236509 and included JavaFX RT and Scene Builder JIRAs.
will be fixed soon for dev/8.0
Actually a separate defect, even with improved namespace support. Note you cannot have two xmlns attributes, it's a XML level error.
Fixed in rev http://hg.netbeans.org/jet-main/rev/05316f8cbcef
Integrated into 'main-silver', will be available in build *201310040001* on http://bits.netbeans.org/dev/nightly/ (upload may still be in progress)
User: Svata Dedic <email@example.com>
Log: #236508: Missing error messages added, I18N added
Is blocked until bug 236509 fix becomes a 7.4 patch.
Verified Fixed in NetBeans 7.4-patch1