Sorry I missed setting the Severity field.

Same issue here. Changing the Java version did not help either:

$ java --version
openjdk 11.0.19 2023-04-18
OpenJDK Runtime Environment (build 11.0.19+7)
OpenJDK 64-Bit Server VM (build 11.0.19+7, mixed mode)

As a work around: JOSM starts when using jre8-openjdk. However, according to upstream it _should_ at least work with java-17 (which is doesn't for me even with java17-openjfx installed).

Running `josm` in terminal leads to error. However `java -jar /usr/share/java/josm/josm.jar` works with both jre-openjdk and jre17-openjdk. Looks like issue with `/usr/bin/josm` script. Also newer version 18746 has been released.

Same here, `java -jar /usr/share/java/josm/josm.jar` works.
```sh
$ pacman -Qs jre
local/jre-openjdk 20.0.1.u9-3
OpenJDK Java 20 full runtime environment
local/jre-openjdk-headless 20.0.1.u9-3
OpenJDK Java 20 headless runtime environment
```

Same here.
```
openjdk 20.0.1 2023-04-18
OpenJDK Runtime Environment (build 20.0.1+9)
OpenJDK 64-Bit Server VM (build 20.0.1+9, mixed mode, sharing)
```
The issue is still present.

Also having this issue.

Possibly relevant: https://bugs.archlinux.org/task/72953

The josm-stable AUR package has the same version of JOSM but its much shorter /usr/bin/josm script works:

#!/bin/sh
# source application-specific settings
while true; do
JOSM_ARGS=
[ -f /etc/conf.d/josm ] && . /etc/conf.d/josm
CLASSPATH="/usr/share/java/josm/josm.jar"
java ${JOSM_ARGS} -cp "${CLASSPATH}" -Djosm.restart=true org.openstreetmap.josm.gui.MainApplication "$@"
[ $? -eq 9 ] || break
done

Also running into this.

```
java --version
openjdk 20.0.2 2023-07-18
OpenJDK Runtime Environment (build 20.0.2+9)
OpenJDK 64-Bit Server VM (build 20.0.2+9, mixed mode, sharing)
```

Same, `josm-stable` seems to work and provides same package.

I use it as a workaround for now

I noticed `JAVAFX_HOME="${JAVAFX_HOME:-/usr/share/openjfx/lib}"` in /usr/bin/josm and added a `JAVAFX_HOME=/usr/lib/jvm/default/lib/` line to /etc/conf.d/josm (java-openfx installs the needed .jar files to /usr/lib/jvm/java-20-openjdk/lib/; there’s no /usr/share/openjfx on my system), which just made it complain about "java.lang.LayerInstantiationException: Package jdk.internal.jimage in both module jrt.fs and module java.base" instead and I don’t know Java well enough to know how to fix or work around that.

Edit: New error seems to be an issue with how Arch installs OpenJFX into /usr/lib/jvm: https://stackoverflow.com/a/62899144/5193095
Edit 2: Based on that SO answer I adjusted JAVAFX_HOME in /etc/conf.d/josm to `JAVAFX_HOME=/usr/lib/jvm/default/lib/javafx.base.jar:/usr/lib/jvm/default/lib/javafx.web.jar:/usr/lib/jvm/default/lib/javafx.controls.jar:/usr/lib/jvm/default/lib/javafx.swing.jar:/usr/lib/jvm/default/lib/javafx.media.jar:/usr/lib/jvm/default/lib/javafx.graphics.jar:/usr/lib/jvm/default/lib/javafx.fxml.jar` and JOSM seems to work now, so that is another possible workaround for the time being if you want to minimise your AUR reliance. :) (`JAVAFX_HOME=/usr/lib/jvm/default/lib/javafx.base.jar:/usr/lib/jvm/default/lib/javafx.web.jar:/usr/lib/jvm/default/lib/javafx.controls.jar:/usr/lib/jvm/default/lib/javafx.swing.jar:/usr/lib/jvm/default/lib/javafx.media.jar:/usr/lib/jvm/default/lib/javafx.graphics.jar` seems to be the minimal required JAVAFX_HOME, but I’ve included javafx.fxml.jar in case anything actually uses that that just isn’t referenced yet at boot time. Not sure if Java actually works like that or not, but including it also doesn’t seem to break it, so 🤷)

Edit 3: Package with workaround‐fixes (and version bump) can be found at https://gitlab.archlinux.org/freso/josm/-/tree/47b89da2f9ad92e5757121e63031b86b295af29f if anyone is interested. I’d suggest to change $pkgrel to 0 so you’ll get the update from the repository whenever it gets fixed in the package proper. :)

`/usr/bin/josm` is a debian-specific script. Maybe that's root cause of problem? See also https://bugs.archlinux.org/task/79420.

Actually, same issue here, also when starting josm.jar directly.

Same error:

dpkg: no packages found matching openjdk-*-jre
dpkg: no packages found matching openjdk-*-jre:amd64
Using /usr/bin/java to execute josm.
Error occurred during initialization of boot layer
java.lang.module.FindException: Module javafx.web not found

Installing java-openjfx, that isn't in dependencies (definitively should be) didn't resolved the issue.

Tried by installing java17-openjfx, I have the same issue.

I just noticed that jdk11-openjdk is still on my system, and if I try to remove it pacman complain about few application dependencies on it via java-environment dependence. Maybe the solution should be to switch by one way (don't know which one but removing all dependencies, removing v11 and reinstalling current version (v20) and the packages depending on it, after that.

After:
* removing all old jdk/jre and their dependencies
* force a new installation of last jre-openjdk jre-openjdk-headless jdk-openjdk packages
* installing java-openjfx again
* changed /usr/bin/josm, as said in the https://bugs.archlinux.org/task/78707#comment219130
This works.