Trying to download MapRoulette tasks results in unexpected exception.

[anonymous]

What steps will reproduce the problem?

1. Download MapRoulette plug-in.
2. In the Download window, check the box to download MapRoulette tasks along with selected map data of only a few streets (that I know has available MapRoulette tasks).
3. Notices for unexpected exceptions keep popping up as it tries to download.
4. The notices only stop popping up if I suppress them for this session. After that, JOSM goes blank.

What is the expected result?

It successfully downloads tasks for me to do in JOSM instead of in ID.

What happens instead?

JOSM becomes blank, solid white, and I have to close the program.

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

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2026-08-11 15:36:21 +0200 (Tue, 11 Aug 2026)
Revision:19613
Build-Date:2026-08-12 01:30:51
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (19613 en) Windows 10 64-Bit
OS Build number: Windows 10 Pro 22H2 (19045)
Memory Usage: 348 MB / 8176 MB (100 MB allocated, but free)
Java version: 25.0.3+9-LTS, Eclipse Adoptium, OpenJDK 64-Bit Server VM
Look and Feel: javax.swing.plaf.nimbus.NimbusLookAndFeel
Screen: \Display0 1920x1080x32bpp@144Hz (scaling 1.00×1.00) \Display1 1920x1080x32bpp@59Hz (scaling 1.00×1.00)
Maximum Screen Size: 1920×1080
Best cursor sizes: 16×16→32×32, 32×32→32×32
System property file.encoding: UTF-8
System property sun.jnu.encoding: Cp1252
Locale info: en_US
Numbers with default locale: 1234567890 -> 1234567890
Dataset consistency test: No problems found

Plugins:
+ MapRoulette (87)

Last errors/warnings:
- 00000.317 W: extended font config - overriding 'filename.Malgun_Gothic=malgun.ttf' with 'MALGUN.TTF'
- 00000.318 W: extended font config - overriding 'filename.Myanmar_Text=mmrtext.ttf' with 'MMRTEXT.TTF'
- 00000.318 W: extended font config - overriding 'filename.Mongolian_Baiti=monbaiti.ttf' with 'MONBAITI.TTF'
- 00071.493 E: Handled by bug report queue: java.lang.NullPointerException: Cannot invoke "jakarta.json.JsonValue.toString()" because the return value of "jakarta.json.JsonObject.get(Object)" is null
- 00071.546 E: Handled by bug report queue: java.lang.reflect.InvocationTargetException. Cause: java.lang.NullPointerException: Cannot invoke "jakarta.json.JsonValue.toString()" because the return value of "jakarta.json.JsonObject.get(Object)" is null



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

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: AWT-EventQueue-0 (43) of main
java.lang.NullPointerException: Cannot invoke "jakarta.json.JsonValue.toString()" because the return value of "jakarta.json.JsonObject.get(Object)" is null
	at org.openstreetmap.josm.plugins.maproulette.api.ChallengeAPI.parseChallengePriority(ChallengeAPI.java:321)
	at org.openstreetmap.josm.plugins.maproulette.api.ChallengeAPI.parseChallenge(ChallengeAPI.java:279)
	at org.openstreetmap.josm.plugins.maproulette.api.ChallengeAPI.challenge(ChallengeAPI.java:233)
	at org.openstreetmap.josm.plugins.maproulette.api_caching.ChallengeCache.challenge(ChallengeCache.java:57)
	at org.openstreetmap.josm.plugins.maproulette.api_caching.ChallengeCache.isHidden(ChallengeCache.java:36)
	at org.openstreetmap.josm.plugins.maproulette.api_caching.TaskCache.isHidden(TaskCache.java:50)
	at org.openstreetmap.josm.plugins.maproulette.gui.layer.MapRouletteClusteredPointLayer.paint(MapRouletteClusteredPointLayer.java:221)
	at org.openstreetmap.josm.gui.layer.AbstractMapViewPaintable$CompatibilityModeLayerPainter.paint(AbstractMapViewPaintable.java:27)
	at org.openstreetmap.josm.gui.MapView.paintLayer(MapView.java:487)
	at org.openstreetmap.josm.gui.MapView.drawMapContent(MapView.java:585)
	at org.openstreetmap.josm.gui.MapView.paint(MapView.java:509)
	at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:961)
	at java.desktop/javax.swing.JComponent.paint(JComponent.java:1137)
	at java.desktop/javax.swing.JComponent.paintToOffscreen(JComponent.java:5324)
	at java.desktop/javax.swing.RepaintManager$PaintManager.paintDoubleBufferedImpl(RepaintManager.java:1599)
	at java.desktop/javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1574)
	at java.desktop/javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1512)
	at java.desktop/javax.swing.RepaintManager.paint(RepaintManager.java:1279)
	at java.desktop/javax.swing.JComponent._paintImmediately(JComponent.java:5272)
	at java.desktop/javax.swing.JComponent.paintImmediately(JComponent.java:5082)
	at java.desktop/javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:825)
	at java.desktop/javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:788)
	at java.desktop/javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738)
	at java.desktop/javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1840)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:323)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:723)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:702)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:117)
	at java.desktop/java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:187)
	at java.desktop/java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:229)
	at java.desktop/java.awt.Dialog.show(Dialog.java:1051)
	at java.desktop/java.awt.Component.show(Component.java:1690)
	at java.desktop/java.awt.Component.setVisible(Component.java:1637)
	at java.desktop/java.awt.Window.setVisible(Window.java:982)
	at java.desktop/java.awt.Dialog.setVisible(Dialog.java:989)
	at org.openstreetmap.josm.gui.progress.swing.PleaseWaitProgressMonitor.lambda$doBeginTask$3(PleaseWaitProgressMonitor.java:255)
	at org.openstreetmap.josm.gui.progress.swing.PleaseWaitProgressMonitor.lambda$doInEDT$0(PleaseWaitProgressMonitor.java:113)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:323)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:723)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:702)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)