JOSM top menu, mainly Imagery layer is very slow

[mapping@…]

What steps will reproduce the problem?

1. start JOSM
2. download map
3. enable images layer

What is the expected result?

Imagery menu should open without delay

What happens instead?

3-5 seconds delay after menu Imagery has been clicked.

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

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-01-02 22:34:59 +0100 (Thu, 02 Jan 2020)
Revision:15628
Build-Date:2020-01-02 21:52:31
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (15628 en_AU) Linux Ubuntu 19.10
Memory Usage: 446 MB / 1918 MB (63 MB allocated, but free)
Java version: 11.0.5+10-post-Ubuntu-0ubuntu1.1, Private Build, OpenJDK 64-Bit Server VM
Screen: :0.0 1600x900
Maximum Screen Size: 1600x900
Java package: openjdk-11-jre:amd64-11.0.5+10-0ubuntu1.1
Java ATK Wrapper package: libatk-wrapper-java:all-0.35.0-3
libcommons-logging-java: libcommons-logging-java:all-1.2-2
fonts-noto: fonts-noto:all-20181227-1
VM arguments: [-Djosm.restart=true, -Djava.net.useSystemProxies=true]
Dataset consistency test: No problems found

Plugins:
+ DirectDownload (35248)
+ Mapillary (1.5.20)
+ OpenStreetCam (280)
+ apache-commons (35092)
+ apache-http (35092)
+ buildings_tools (35248)
+ conflation (0.6.4)
+ jna (35092)
+ jts (35122)
+ rex (53)
+ scripting (30796)
+ tageditor (35258)
+ terracer (35248)
+ turnlanes-tagging (283)
+ turnrestrictions (35248)
+ utilsplugin2 (35248)

Tagging presets:
+ https://josm.openstreetmap.de/josmfile?page=Presets/Bus_lanes&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/BuildingPreset&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/LaneAttributes&zip=1

Map paint styles:
+ https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/BesideTheRoad_Speed&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/SlovakiaBicycleRoutes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Streets&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Maxspeed&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Styles/ParkingLanes&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Styles/Schools&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Sidewalks&zip=1
+ ${HOME}/Software/osm-nsw-address-import/src/elemstyles.mapcss

Last errors/warnings:
- W: Failed to load https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico, use cached file and retry next time: java.io.IOException: The requested URL https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico was not found
- E: Failed to locate image 'https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico'
- W: Failed to load https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico, use cached file and retry next time: java.io.IOException: The requested URL https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico was not found
- E: Failed to locate image 'https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico'
- W: Failed to load https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico, use cached file and retry next time: java.io.IOException: The requested URL https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico was not found
- E: Failed to locate image 'https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico'
- W: Failed to load https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico, use cached file and retry next time: java.io.IOException: The requested URL https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico was not found
- E: Failed to locate image 'https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico'
- W: Failed to load https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico, use cached file and retry next time: java.io.IOException: The requested URL https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico was not found
- E: Failed to locate image 'https://www.spatial.nsw.gov.au/__data/assets/file/0010/210520/favicon.ico'

[Don-vip]

Closed as duplicate of #18534.
australian icon links changed recently, see ​https://github.com/osmlab/editor-layer-index/pull/759/files
The JOSM code issue has already been fixed in #18534.