Error dialog when switching to map settings tab

[the_redburn]

What steps will reproduce the problem?

I couldn't reproduce it. The first time, I did:

1. Open settings
2. Switch to map settings tab

What is the expected result?

What happens instead?

Error dialog suggesting I report it.

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

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2018-03-04 16:20:37 +0100 (Sun, 04 Mar 2018)
Build-Date:2018-03-04 15:24:13
Revision:13500
Redirecting:to URL 'https://josm.openstreetmap.de/svn/trunk':
Relative:URL: ^/trunk

Identification: JOSM/1.5 (13500 fr) Windows 7 64-Bit
OS Build number: Windows 7 Ultimate (7601)
Memory Usage: 247 MB / 247 MB (69 MB allocated, but free)
Java version: 1.8.0_161-b12, Oracle Corporation, Java HotSpot(TM) Client VM
Screen: \Display0 1920x1080
Maximum Screen Size: 1920x1080
VM arguments: [-Djava.security.manager, -Djava.security.policy=file:<java.home>\lib\security\javaws.policy, -DtrustProxy=true, -Djnlpx.home=<java.home>\bin, -Djnlpx.origFilenameArg=%UserProfile%\AppData\LocalLow\Sun\Java\Deployment\cache\6.0\56\1ee8cfb8-61b0b2b7, -Djnlpx.remove=false, -Djava.util.Arrays.useLegacyMergeSort=true, -Djnlpx.splashport=21130, -Djnlp.application.href=https://josm.openstreetmap.de/download/josm.jnlp, -Djnlpx.jvm=<java.home>\bin\javaw.exe]
Dataset consistency test: No problems found

Plugins:
+ HouseNumberTaggingTool (34074)
+ conflation (0.5.6)
+ imagery_offset_db (33774)
+ jts (32699)
+ reltoolbox (33708)
+ reverter (34036)
+ undelete (33980)
+ utilsplugin2 (33991)

Map paint styles:
- https://github.com/bastik/mapcss-tools/raw/osm/mapnik2mapcss/osm-results/mapnik.zip
+ https://josm.openstreetmap.de/josmfile?page=Styles/Traffic_signs&zip=1

Last errors/warnings:
- W: java.io.IOException: L'URL demandée https://josm.openstreetmap.de/josmfile?page=Styles/Traffic_signs&zip=1 n'a pas été trouvée
- W: Échec du chargement des styles de rendu de 'https://josm.openstreetmap.de/josmfile?page=Styles/Traffic_signs&zip=1'. Lʼexception était : java.io.IOException: L'URL demandée https://josm.openstreetmap.de/josmfile?page=Styles/Traffic_signs&zip=1 n'a pas été trouvée
- E: java.io.IOException: L'URL demandée https://josm.openstreetmap.de/josmfile?page=Styles/Traffic_signs&zip=1 n'a pas été trouvée
- W: Initializing map style https://josm.openstreetmap.de/josmfile?page=Styles/Traffic_signs&zip=1 completed in 154 ms (1 errors, 0 warnings)
- W: No configuration settings found.  Using hardcoded default values for all pools.
- E: Handled by bug report queue: java.awt.IllegalComponentStateException: component must be showing on the screen to determine its location
- E: Handled by bug report queue: java.awt.IllegalComponentStateException: component must be showing on the screen to determine its location


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

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: AWT-EventQueue-2 (53) of javawsApplicationThreadGroup
java.awt.IllegalComponentStateException: component must be showing on the screen to determine its location
	at java.awt.Component.getLocationOnScreen_NoTreeLock(Unknown Source)
	at java.awt.Component.getLocationOnScreen(Unknown Source)
	at javax.swing.text.JTextComponent$InputMethodRequestsHandler.getTextLocation(Unknown Source)
	at sun.awt.im.InputMethodContext.getTextLocation(Unknown Source)
	at sun.awt.windows.WInputMethod$1.run(Unknown Source)
	at java.awt.event.InvocationEvent.dispatch(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.pumpEventsForFilter(Unknown Source)
	at java.awt.WaitDispatchSupport$2.run(Unknown Source)
	at java.awt.WaitDispatchSupport$4.run(Unknown Source)
	at java.awt.WaitDispatchSupport$4.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.awt.WaitDispatchSupport.enter(Unknown Source)
	at java.awt.Dialog.show(Unknown Source)
	at java.awt.Component.show(Unknown Source)
	at java.awt.Component.setVisible(Unknown Source)
	at java.awt.Window.setVisible(Unknown Source)
	at java.awt.Dialog.setVisible(Unknown Source)
	at org.openstreetmap.josm.gui.preferences.PreferenceDialog.setVisible(PreferenceDialog.java:141)
	at org.openstreetmap.josm.actions.PreferencesAction.run(PreferencesAction.java:112)
	at org.openstreetmap.josm.actions.PreferencesAction.actionPerformed(PreferencesAction.java:101)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
	at javax.swing.AbstractButton.doClick(Unknown Source)
	at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source)
	at javax.swing.plaf.basic.BasicMenuItemUI$Handler.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 #15801.