java.lang.AssertionError at org.netbeans.modules.xml.xdm.diff.MergeDiff.applyChildrenDiffs(MergeDiff.java:142) at org.netbeans.modules.xml.xdm.diff.MergeDiff.merge(MergeDiff.java:108) at org.netbeans.modules.xml.xdm.XDMModel.mergeDiff(XDMModel.java:251) at org.netbeans.modules.xml.xdm.XDMModel.finishSync(XDMModel.java:218) at org.netbeans.modules.xml.xdm.XDMModel.sync(XDMModel.java:158) at org.netbeans.modules.xml.xdm.xam.XDMAccess.sync(XDMAccess.java:141) at org.netbeans.modules.xml.xam.AbstractModel.sync(AbstractModel.java:259) at org.netbeans.modules.xml.xam.AbstractModel$1.run(AbstractModel.java:652) at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:602) at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1070) Caused: org.openide.util.RequestProcessor$FastItem: task failed due to: java.lang.AssertionError