can't add new member to relation (multipolygon)

[LLlypuk82]

What steps will reproduce the problem?

What is the expected result?

What happens instead?

Please provide any additional information below. Attach a screenshot if possible.

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2017-10-03 01:19:13 +0200 (Tue, 03 Oct 2017)
Build-Date:2017-10-03 01:40:27
Revision:12915
Relative:URL: ^/trunk

Identification: JOSM/1.5 (12915 ru) Windows 10 64-Bit
OS Build number: Windows 10 Enterprise 2016 LTSB 1607 (14393)
Memory Usage: 727 MB / 1813 MB (233 MB allocated, but free)
Java version: 1.8.0_121-b13, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: \Display0 1920x1080
Maximum Screen Size: 1920x1080
Dataset consistency test: No problems found

Plugins:
+ HouseNumberTaggingTool (33160)
+ OpeningHoursEditor (33185)
+ PicLayer (33385)
+ buildings_tools (33004)
+ imagery_offset_db (33547)
+ measurement (33088)
+ reltoolbox (33530)
+ reverter (33572)
+ tag2link (33382)
+ tageditor (33579)
+ turnlanes-tagging (254)
+ turnrestrictions (33537)
+ utilsplugin2 (33677)

Tagging presets:
+ https://raw.githubusercontent.com/yopaseopor/traffic_signs_preset_JOSM/master/BY.zip
+ https://josm.openstreetmap.de/josmfile?page=Presets/Quick-highways&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Quick-stops&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/NewTags&zip=1
+ http://zibi.openstreetmap.org.pl/kendzi/k/Simple3dPreset/s3db-preset.zip
+ https://josm.openstreetmap.de/josmfile?page=Presets/Crafts&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/speed_camera_in_Belarus&zip=1
+ F:\Install\Navigation\JOSM\Preset_names.zip
+ F:\Install\Navigation\JOSM\Presets_wood_proreties.zip

Map paint styles:
+ https://www.dropbox.com/s/qo3ai47fpv241jf/Styles_Fixme_and_Notes.zip?raw=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1
- https://github.com/igitov/forest-josm-style/archive/master.zip
+ https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Streets&zip=1

Last errors/warnings:
- W: Обновить модули - org.openstreetmap.josm.plugins.PluginHandler$UpdatePluginsMessagePanel[,0,0,0x0,invalid,layout=java.awt.GridBagLayout,alignmentX=0.0,alignmentY=0.0,border=,flags=9,maximumSize=,minimumSize=,preferredSize=]
- W: Предупреждение: Заготовка тегов "leaf_type-Type": Игнорируем атрибут 'values' в элементах 'list_entry'.
- W: No configuration settings found.  Using hardcoded default values for all pools.
- E: Handled by bug report queue: java.lang.IllegalArgumentException: Parameter 'data' must not be null


=== REPORTED CRASH DATA ===
BugReportExceptionHandler#handleException:
No data collected.

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: AWT-EventQueue-0 (19) of main
java.lang.IllegalArgumentException: Parameter 'data' must not be null
	at org.openstreetmap.josm.tools.CheckParameterUtil.ensureParameterNotNull(CheckParameterUtil.java:135)
	at org.openstreetmap.josm.command.Command.<init>(Command.java:173)
	at org.openstreetmap.josm.command.ChangeCommand.<init>(ChangeCommand.java:63)
	at org.openstreetmap.josm.command.ChangeCommand.<init>(ChangeCommand.java:37)
	at relcontext.relationfix.MultipolygonFixer.fixRelation(MultipolygonFixer.java:48)
	at relcontext.actions.SortAndFixAction.fixRelation(SortAndFixAction.java:81)
	at relcontext.actions.AddRemoveMemberAction.actionPerformed(AddRemoveMemberAction.java:78)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
	at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
	at java.awt.Component.processMouseEvent(Unknown Source)
	at javax.swing.JComponent.processMouseEvent(Unknown Source)
	at java.awt.Component.processEvent(Unknown Source)
	at java.awt.Container.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Window.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
	at java.awt.EventQueue.access$500(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.run(Unknown Source)

[Don-vip]

Closed as duplicate of #15320.