Incorrect message saying gpx file should be saved

[Adrian]

What steps will reproduce the problem?

1. Put the attached .gpx file in a convenient location.
2. Using a text editor, edit the path in the attached .jos file so that it points to the gpx file.
3. Open the jos file.
4. Delete the gpx layer.

What is the expected result?

The gpx layer is deleted.

What happens instead?

A dialog opens saying the gpx file should be saved.

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

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2021-04-01 23:17:01 +0200 (Thu, 01 Apr 2021)
Revision:17702
Build-Date:2021-04-01 21:46:03
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (17702 en_GB) Mac OS X 10.14.6
OS Build number: Mac OS X 10.14.6 (18G8022)
Memory Usage: 396 MB / 4096 MB (74 MB allocated, but free)
Java version: 15.0.2+7, AdoptOpenJDK, OpenJDK 64-Bit Server VM
Look and Feel: com.apple.laf.AquaLookAndFeel
Screen: Display 458669421 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

Plugins:
+ ImportImagePlugin (35567)
+ InfoMode (35543)
+ PicLayer (2a9aa7a)
+ apache-commons (35524)
+ cadastre-fr (35727)
+ editgpx (35562)
+ ejml (35458)
+ geotools (35458)
+ http2 (35427)
+ imagery_offset_db (35640)
+ jaxb (35543)
+ jts (35458)
+ log4j (35458)
+ measurement (35640)
+ opendata (35640)
+ photo_geotagging (35715)
+ poly (35640)
+ reverter (35688)
+ turnrestrictions (35640)
+ undelete (35640)
+ utilsplugin2 (35691)
+ waydownloader (35640)

[skyper]

Iam not sure if it is the same or another problem but I noticed some problems with files in sessions, too, in my case .osm. Thought it is related to have the file included in the session and additionally having it saved as local file.

[Bjoeni]

Closed as duplicate of #20913.
Your ticket was first, but I guess the referenced ticket is the active one now.