StartupWMClass is wrong with 30.0.4 in Ubuntu 24.04

[senique]

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Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

1. Install draw.io Desktop 30.0.4 on Ubuntu 24.04
2. Launch draw.io from the application menu
3. Run xprop WM_CLASS and click on the draw.io window
4. Observe the output:
   WM_CLASS(STRING) = "draw-io", "draw-io"
5. Check the installed .desktop file and see:
   StartupWMClass=draw.io
6. Notice that the icon (Icon=drawio) cannot be resolved correctly

Expected behavior
The StartupWMClass should match the actual WM_CLASS value reported by the window. Either:

StartupWMClass=draw-io

or the application should set its WM_CLASS to:

draw.io

This would allow the desktop environment to correctly match the window to its icon and launcher.

Screenshots
no

draw.io version (In the Help->About menu of the draw.io editor):

• draw.io Desktop 30.0.4

Desktop (please complete the following information):

• OS: Ubuntu 24.04 LTS
• Desktop Environment: GNOME Shell
• Installation Method: .deb package

Additional context
no

[draw-io-triage-bot]

👋 Thank you for opening this issue!

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Summary: The StartupWMClass in the draw.io .desktop file is set to 'draw.io' but the actual WM_CLASS of the application window is 'draw-io' on Ubuntu 24.04 with version 30.0.4, causing the desktop environment to fail to correctly associate the window with its launcher and icon. This appears to be a regression of the previously fixed issue #759.

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💡 Possible Solution Found

We found a potentially relevant solution in a previous issue:

This issue was previously reported and addressed in #759, which dealt with the same mismatch between StartupWMClass in the .desktop file and the actual WM_CLASS of the draw.io window on Ubuntu. The issue was closed as resolved. However, it appears this regression may have been reintroduced in version 30.0.4. As a workaround, you can manually edit the .desktop file (typically at /usr/share/applications/drawio.desktop) and change 'StartupWMClass=draw.io' to 'StartupWMClass=draw-io' to match the actual WM_CLASS reported by xprop.

📎 Source: #759

Please check if this addresses your issue. If not, let us know what's different about your situation.

🔍 Possible Related Issues

This issue might be related to existing issues:

🔴 #759 - Wrong StartupWMClass in "/usr/share/applications/drawio.desktop" file (Ubuntu)
This is the exact same issue — a mismatch between the StartupWMClass value in the .desktop file and the actual WM_CLASS of the draw.io window on Ubuntu. It appears to be a regression of this previously fixed bug.

Please check if any of these address your issue. If this is a duplicate, we may close this issue and continue the conversation there.

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_{🤖 This is an automated response to help with initial triage. A human maintainer will review this issue. If you've provided all the requested information, no further action is needed - we'll get back to you soon!}

[senique]

Temporary workaround:

1. Edit the .desktop file and change:

   StartupWMClass=draw-io
   

2. Copy the icon file to:

   /usr/share/pixmaps/drawio.png
   

[senique]

The following files likely need to be updated to fix the WM_CLASS mismatch:

• electron-builder-linux-mac.json
• electron-builder-snap.json

Change:

"StartupWMClass": "draw.io"

to:

"StartupWMClass": "draw-io"

[rishav2404]

Yes same problem happened with me as well. I am using Fedora 43/44 workstation.

The was I solved it:

cp /usr/share/applications/drawio.desktop ~/.local/share/applications/

nano ~/.local/share/applications/drawio.desktop

You will see something like this:

[Desktop Entry]
Name=drawio
Exec=/opt/drawio/drawio %U
Terminal=false
Type=Application
Icon=drawio
StartupWMClass=draw.io
Comment=draw.io desktop
MimeType=application/vnd.jgraph.mxfile;application/vnd.visio;
Categories=Graphics;

• Now in here, change the

 StartupWMClass=draw.io

to

 StartupWMClass=draw-io

Ctrl + o, then press Enter, then Ctrl +x

then,

update-desktop-database ~/.local/share/applications