Bogus "editing failed" message when loading a map area from OSM

[anonymous]

What steps will reproduce the problem?

1. Load JOSM
2. Open a map, eg ​https://www.openstreetmap.org/?mlat=51.568171977996826&mlon=0.03954648971557617#map=18/51.56797/0.03992
3. Click on EDIT button

What is the expected result?

The map area is loaded in OSM

What happens instead?

The map area is loaded in OSM, but is preceded by a bogus Editing Failed message

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

Firefox console logs this:

10:04:48.609 GEThttp://127.0.0.1:8111/load_and_zoom?left=0.03467215766906739&top=51.56956121773012&right=0.04517184028625489&bottom=51.566380223035274
[HTTP/1.1 200 OK 648ms]

GET

​http://127.0.0.1:8111/load_and_zoom?left=0.03467215766906739&top=51.56956121773012&right=0.04517184028625489&bottom=51.566380223035274

Status200
OK
VersionHTTP/1.1
Transferred179 B (4 B size)

Access-Control-Allow-Origin

*

Content-length

4

Content-type

text/plain; charset=utf-8

Date

Wed May 05 10:04:49 BST 2021

Server

JOSM RemoteControl

Accept

text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8

Accept-Encoding

gzip, deflate

Accept-Language

en-GB

Connection

keep-alive

Host

127.0.0.1:8111

Upgrade-Insecure-Requests

1

User-Agent

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:88.0) Gecko/20100101 Firefox/88.0

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2021-04-27 20:35:33 +0200 (Tue, 27 Apr 2021)
Build-Date:2021-04-27 21:58:39
Revision:17833
Relative:URL: ^/trunk

Identification: JOSM/1.5 (17833 en_GB) Windows 10 64-Bit
OS Build number: Windows 10 Pro 2009 (19042)
Memory Usage: 349 MB / 3628 MB (201 MB allocated, but free)
Java version: 1.8.0_281-b09, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Look and Feel: com.sun.java.swing.plaf.windows.WindowsLookAndFeel
Screen: \Display0 1920×1080 (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: Cp1252
System property sun.jnu.encoding: Cp1252
Locale info: en_GB
Numbers with default locale: 1234567890 -> 1234567890
Dataset consistency test: No problems found

Plugins:
+ AddrInterpolation (35640)
+ DirectDownload (35640)
+ PicLayer (2a9aa7a)
+ ShapeTools (1240)
+ apache-commons (35524)
+ apache-http (35589)
+ buildings_tools (35740)
+ fieldpapers (v0.5.0)
+ imagery_offset_db (35640)
+ javafx-windows (35655)
+ jna (35662)
+ merge-overlap (35640)
+ photoadjust (35640)
+ terracer (35640)
+ turnrestrictions (35640)
+ utilsplugin2 (35691)

Tagging presets:
+ https://josm.openstreetmap.de/josmfile?page=Presets/Addr2&zip=1

Map paint styles:
- https://josm.openstreetmap.de/josmfile?page=Styles/Fixme&zip=1
+ C:\Users\pcs3\AppData\Roaming\JOSM\custom\bigFixmeNodes.mapcss
+ C:\Users\pcs3\AppData\Roaming\JOSM\custom\redHouseNumbers.mapcss
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Streets&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_buildings&zip=1

Last errors/warnings:
- 00030.745 W: Failed to load Mappaint styles from 'C:\Users\pcs3\AppData\Roaming\JOSM\custom\bigFixmeNodes.mapcss'. Exception was: java.nio.file.NoSuchFileException: C:\Users\pcs3\AppData\Roaming\JOSM\custom\bigFixmeNodes.mapcss
- 00030.746 E: java.nio.file.NoSuchFileException: C:\Users\pcs3\AppData\Roaming\JOSM\custom\bigFixmeNodes.mapcss
- 00030.808 E: java.nio.file.NoSuchFileException: C:\Users\pcs3\AppData\Roaming\JOSM\custom
- 00030.830 W: Initializing map style C:\Users\pcs3\AppData\Roaming\JOSM\custom\bigFixmeNodes.mapcss completed in 66 ms (1 errors, 0 warnings)
- 00030.831 W: Failed to load Mappaint styles from 'C:\Users\pcs3\AppData\Roaming\JOSM\custom\redHouseNumbers.mapcss'. Exception was: java.nio.file.NoSuchFileException: C:\Users\pcs3\AppData\Roaming\JOSM\custom\redHouseNumbers.mapcss
- 00030.835 E: java.nio.file.NoSuchFileException: C:\Users\pcs3\AppData\Roaming\JOSM\custom\redHouseNumbers.mapcss
- 00030.856 E: java.nio.file.NoSuchFileException: C:\Users\pcs3\AppData\Roaming\JOSM\custom
- 00030.857 W: Initializing map style C:\Users\pcs3\AppData\Roaming\JOSM\custom\redHouseNumbers.mapcss completed in 26 ms (1 errors, 0 warnings)