OSM server error: "Opening and ending tag mismatch"

[mikini]

Hi there.

After a short editing session I uploaded changes opening a new changeset and leaving it open. When trying to save changes afterwards I got a nice dialog with a message similar to the exception below ("Fatal error: Opening and ending tag mismatch: anonymous line 3 and changeset at :7").

I went to the Upload dialog's Changeset tab and tried to update my opened changeset list and toggled "Upload to a new changeset" and back to "Upload to an existing changeset" selecting the only open changeset. This made the upload succeed.

Shortly after I was inspecting the history of a way (137307317) and when clicking on a node in the Nodes list of the Nodes tab the exception below occured. Screenshot of this is attached.

Additionally I got this error when using the pre-filled form link in the exception dialog (this was before creating an account on Trac):
"Genshi UnicodeDecodeError error while rendering template '/usr/local/lib/python2.7/dist-packages/Trac-1.0.9-py2.7.egg/trac/ticket/templates/ticket.html', line 251, char -1"

Thanks

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2016-03-13 01:17:21 +0100 (Sun, 13 Mar 2016)
Build-Date:2016-03-13 02:35:00
Revision:9979
Relative:URL: ^/trunk

Identification: JOSM/1.5 (9979 en) Linux Ubuntu 15.10
Memory Usage: 305 MB / 1682 MB (100 MB allocated, but free)
Java version: 1.7.0_95-b00, Oracle Corporation, OpenJDK 64-Bit Server VM
Java package: openjdk-7-jre:amd64-7u95-2.6.4-0ubuntu0.15.10.1
Dataset consistency test: No problems found

Plugins:
- imagery_offset_db (32046)
- utilsplugin2 (32099)

Last errors/warnings:
- E: Error header: Cannot parse valid changeset from xml string <?xml version='1.0' encoding='UTF-8'?>,<osm version='0.6' generator='JOSM'>,<changeset  id='38038262' user='<anonymous>' uid='-1' open='true'>,<tag k='comment' v='Add some details around Guldager Mølledam.' />,<tag k='created_by' v='JOSM/1.5 (9979 en)' />,<tag k='source' v='survey; Geodatastyrelsen (Denmark)' />,</changeset>,</osm>,. Fatal error: Opening and ending tag mismatch: anonymous line 3 and changeset at :7.
- E: org.openstreetmap.josm.io.OsmApiException: ResponseCode=400, Error Header=<Cannot parse valid changeset from xml string <?xml version=1.0 encoding=UTF-8?>,<osm version=0.6 generator=JOSM>,<changeset  id=38038262 user=<anonymous> uid=-1 open=true>,<tag k=comment v=Add some details around Guldager Mølledam. />,<tag k=created_by v=JOSM/1.5 (9979 en) />,<tag k=source v=survey; Geodatastyrelsen (Denmark) />,</changeset>,</osm>,. Fatal error: Opening and ending tag mismatch: anonymous line 3 and changeset at :7.>, Error Body=<Cannot parse valid changeset from xml string <?xml version=1.0 encoding=UTF-8?>
- E: Error header: Cannot parse valid changeset from xml string <?xml version='1.0' encoding='UTF-8'?>,<osm version='0.6' generator='JOSM'>,<changeset  id='38038262' user='<anonymous>' uid='-1' open='true'>,<tag k='comment' v='Add some details around Guldager Mølledam.' />,<tag k='created_by' v='JOSM/1.5 (9979 en)' />,<tag k='source' v='survey; Geodatastyrelsen (Denmark)' />,</changeset>,</osm>,. Fatal error: Opening and ending tag mismatch: anonymous line 3 and changeset at :7.
- E: org.openstreetmap.josm.io.OsmApiException: ResponseCode=400, Error Header=<Cannot parse valid changeset from xml string <?xml version=1.0 encoding=UTF-8?>,<osm version=0.6 generator=JOSM>,<changeset  id=38038262 user=<anonymous> uid=-1 open=true>,<tag k=comment v=Add some details around Guldager Mølledam. />,<tag k=created_by v=JOSM/1.5 (9979 en) />,<tag k=source v=survey; Geodatastyrelsen (Denmark) />,</changeset>,</osm>,. Fatal error: Opening and ending tag mismatch: anonymous line 3 and changeset at :7.>, Error Body=<Cannot parse valid changeset from xml string <?xml version=1.0 encoding=UTF-8?>
- E: java.lang.NullPointerException

java.lang.NullPointerException
	at org.openstreetmap.josm.gui.history.NodeListTableCellRenderer.renderNode(NodeListTableCellRenderer.java:37)
	at org.openstreetmap.josm.gui.history.NodeListTableCellRenderer.getTableCellRendererComponent(NodeListTableCellRenderer.java:57)
	at javax.swing.JTable$AccessibleJTable.getAccessibleChild(JTable.java:7044)
	at javax.swing.JTable$AccessibleJTable.getAccessibleAt(JTable.java:7431)
	at javax.swing.JTable$AccessibleJTable.valueChanged(JTable.java:6946)
	at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:184)
	at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:164)
	at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:211)
	at javax.swing.DefaultListSelectionModel.changeSelection(DefaultListSelectionModel.java:405)
	at javax.swing.DefaultListSelectionModel.changeSelection(DefaultListSelectionModel.java:415)
	at javax.swing.DefaultListSelectionModel.setSelectionInterval(DefaultListSelectionModel.java:459)
	at javax.swing.JTable.changeSelectionModel(JTable.java:2389)
	at javax.swing.JTable.changeSelection(JTable.java:2458)
	at javax.swing.plaf.basic.BasicTableUI$Handler.adjustSelection(BasicTableUI.java:1109)
	at javax.swing.plaf.basic.BasicTableUI$Handler.mousePressed(BasicTableUI.java:1032)
	at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:280)
	at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:279)
	at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:279)
	at java.awt.Component.processMouseEvent(Component.java:6513)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3312)
	at java.awt.Component.processEvent(Component.java:6281)
	at java.awt.Container.processEvent(Container.java:2229)
	at java.awt.Component.dispatchEventImpl(Component.java:4872)
	at java.awt.Container.dispatchEventImpl(Container.java:2287)
	at java.awt.Component.dispatchEvent(Component.java:4698)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4489)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
	at java.awt.Container.dispatchEventImpl(Container.java:2273)
	at java.awt.Window.dispatchEventImpl(Window.java:2719)
	at java.awt.Component.dispatchEvent(Component.java:4698)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:747)
	at java.awt.EventQueue.access$300(EventQueue.java:103)
	at java.awt.EventQueue$3.run(EventQueue.java:706)
	at java.awt.EventQueue$3.run(EventQueue.java:704)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:77)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
	at java.awt.EventQueue$4.run(EventQueue.java:720)
	at java.awt.EventQueue$4.run(EventQueue.java:718)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:77)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:717)
	at org.GNOME.Accessibility.AtkWrapper$5.dispatchEvent(AtkWrapper.java:697)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)