Went to close JOSM after leaving it idle for some time (a few hours), and it reported this exception.

[anonymous]

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.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2021-07-12 02:41:41 +0200 (Mon, 12 Jul 2021)
Revision:18004
Build-Date:2021-07-12 00:42:49
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (18004 en_GB) Linux Mint 19.3 Tricia
Memory Usage: 431 MB / 1024 MB (63 MB allocated, but free)
Java version: 11.0.11+9-Ubuntu-0ubuntu2.18.04, Ubuntu, OpenJDK 64-Bit Server VM
Look and Feel: javax.swing.plaf.metal.MetalLookAndFeel
Screen: :0.0 1920×1080 (scaling 1.00×1.00)
Maximum Screen Size: 1920×1080
Best cursor sizes: 16×16→16×16, 32×32→32×32
Environment variable LANG: en_GB.UTF-8
System property file.encoding: UTF-8
System property sun.jnu.encoding: UTF-8
Locale info: en_GB
Numbers with default locale: 1234567890 -> 1234567890
Java package: openjdk-11-jre:amd64-11.0.11+9-0ubuntu2~18.04
fonts-noto: fonts-noto:all-20171026-2

Plugins:
+ alignways (35753)
+ apache-commons (35524)
+ buildings_tools (35756)
+ cadastre-fr (35797)
+ editgpx (35562)
+ ejml (35458)
+ geotools (35458)
+ jts (35458)
+ measurement (35640)
+ print (35640)
+ reverter (35732)
+ undelete (35640)
+ utilsplugin2 (35792)

Last errors/warnings:
- 28895.623 E: Handled by bug report queue: java.lang.NullPointerException



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

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: AWT-EventQueue-0 (19) of main
java.lang.NullPointerException
	at org.openstreetmap.josm.gui.layer.GpxLayer.getAssociatedFile(GpxLayer.java:365)
	at org.openstreetmap.josm.actions.SaveAction.updateEnabledState(SaveAction.java:103)
	at org.openstreetmap.josm.actions.JosmAction$LayerChangeAdapter.layerRemoving(JosmAction.java:451)
	at org.openstreetmap.josm.actions.SaveAction$1.layerRemoving(SaveAction.java:89)
	at org.openstreetmap.josm.gui.layer.LayerManager.fireLayerRemoving(LayerManager.java:476)
	at org.openstreetmap.josm.gui.layer.LayerManager.realRemoveSingleLayer(LayerManager.java:278)
	at org.openstreetmap.josm.gui.layer.MainLayerManager.realRemoveSingleLayer(MainLayerManager.java:307)
	at org.openstreetmap.josm.gui.layer.LayerManager.realRemoveLayer(LayerManager.java:266)
	at org.openstreetmap.josm.gui.layer.LayerManager.lambda$removeLayer$1(LayerManager.java:248)
	at org.openstreetmap.josm.gui.util.GuiHelper.runInEDTAndWaitWithException(GuiHelper.java:246)
	at org.openstreetmap.josm.gui.layer.LayerManager.removeLayer(LayerManager.java:248)
	at org.openstreetmap.josm.gui.layer.LayerManager.realResetState(LayerManager.java:515)
	at org.openstreetmap.josm.gui.layer.MainLayerManager.realResetState(MainLayerManager.java:493)
	at org.openstreetmap.josm.gui.util.GuiHelper.runInEDTAndWaitWithException(GuiHelper.java:246)
	at org.openstreetmap.josm.gui.layer.LayerManager.resetState(LayerManager.java:506)
	at org.openstreetmap.josm.gui.MainTermination.run(MainTermination.java:43)
	at org.openstreetmap.josm.spi.lifecycle.Lifecycle.exitJosm(Lifecycle.java:121)
	at org.openstreetmap.josm.gui.MainApplication.exitJosm(MainApplication.java:520)
	at org.openstreetmap.josm.gui.MainFrame$ExitWindowAdapter.windowClosing(MainFrame.java:198)
	at java.desktop/java.awt.AWTEventMulticaster.windowClosing(AWTEventMulticaster.java:357)
	at java.desktop/java.awt.AWTEventMulticaster.windowClosing(AWTEventMulticaster.java:357)
	at java.desktop/java.awt.AWTEventMulticaster.windowClosing(AWTEventMulticaster.java:357)
	at java.desktop/java.awt.Window.processWindowEvent(Window.java:2078)
	at java.desktop/javax.swing.JFrame.processWindowEvent(JFrame.java:298)
	at java.desktop/java.awt.Window.processEvent(Window.java:2037)
	at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5011)
	at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
	at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2772)
	at java.desktop/java.awt.Component.dispatchEvent(Component.java:4843)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	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)

[skyper]

Closed as duplicate of #21105.