org.w3c.dom.DOMException: INVALID_CHARACTER_ERR: An invalid or illegal XML character is specified. 
   at com.sun.org.apache.xerces.internal.dom.CoreDocumentImpl.checkQName(CoreDocumentImpl.java:2582)
   at com.sun.org.apache.xerces.internal.dom.ElementNSImpl.setName(ElementNSImpl.java:117)
   at com.sun.org.apache.xerces.internal.dom.ElementNSImpl.<init>(ElementNSImpl.java:80)
   at com.sun.org.apache.xerces.internal.dom.CoreDocumentImpl.createElementNS(CoreDocumentImpl.java:2095)
   at org.netbeans.modules.maven.MavenProjectPropsImpl.writeAuxiliaryData(MavenProjectPropsImpl.java:157)
   at org.netbeans.modules.maven.MavenProjectPropsImpl.put(MavenProjectPropsImpl.java:132)
   at org.netbeans.modules.maven.MavenProjectPropsImpl$MergedAuxProperties.put(MavenProjectPropsImpl.java:310)
   at org.netbeans.modules.projectapi.AuxiliaryConfigBasedPreferencesProvider.flushImpl(AuxiliaryConfigBasedPreferencesProvider.java:247)
   at org.netbeans.modules.projectapi.AuxiliaryConfigBasedPreferencesProvider.access$000(AuxiliaryConfigBasedPreferencesProvider.java:86)
   at org.netbeans.modules.projectapi.AuxiliaryConfigBasedPreferencesProvider$2.run(AuxiliaryConfigBasedPreferencesProvider.java:209)
   at org.netbeans.modules.projectapi.AuxiliaryConfigBasedPreferencesProvider$2.run(AuxiliaryConfigBasedPreferencesProvider.java:207)
   at org.openide.util.Mutex.writeAccess(Mutex.java:397)
   at org.netbeans.modules.projectapi.AuxiliaryConfigBasedPreferencesProvider.flush(AuxiliaryConfigBasedPreferencesProvider.java:207)
   at org.netbeans.modules.projectapi.AuxiliaryConfigBasedPreferencesProvider$1.run(AuxiliaryConfigBasedPreferencesProvider.java:174)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1424)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1968)