Drag & Drop doesn't work on Chrome (as of version 144.0.7559.60)

[matti-tumo]

Drag and drop is broken since the latest Chrome update.

To reproduce,

1. go to https://lab.open-roberta.org/
2. Choose any robot
3. Try to add any sensor from the left panel

This should make it obvious, that drag & drop is broken. On Safari the function still works.

This was tested on MacOS 15.7.3 (arm)

[AHberta]

Ursache (Änderung in Chrome 144):
Chrome 144 hat das Verhalten von Mouse-/Pointer-Boundary-Events geändert, wenn Elemente während des Ziehens im DOM entfernt oder neu gerendert werden. Dadurch kann der Hover-/Drag-Zustand „aus dem Tritt geraten“ und Drag & Drop nicht mehr funktionieren.

Abhilfe / Workarounds

• Google Chrome:
  • chrome://flags öffnen
  • nach „Boundary Event Dispatch Tracks Node Removal" suchen
  • auf Disabled stellen
  • Relaunch klicken
• Microsoft Edge: Edge ist Chromium-basiert und daher in derselben Hauptversion vermutlich ebenfalls betroffen. Versucht dasselbe unter edge://flags (das Flag kann dort vorhanden sein oder auch nicht). Wenn das Flag fehlt: Firefox als Workaround verwenden.

Workaround rückgängig machen: Flag wieder auf Default stellen (oder Reset all to default nutzen) und Relaunch.

Hinweis zur Flag-Verfügbarkeit: Chromium-Flags sind temporär/ablaufend und stehen nicht in allen Chrome-/Edge-Channels bzw. Versionen zur Verfügung. Firefox bleibt der verlässlichste client-seitige Workaround.

Alternative: Einen nicht Chromium-basierten Browser verwenden, z. B. Mozilla Firefox (oder Firefox ESR).

---

Cause (Chrome 144 change):
Chrome 144 changed pointer/mouse boundary events when elements are removed/re-rendered in the DOM during dragging, which can break hover/drag state and stop drag & drop.

Workarounds

• Google Chrome
  • Open chrome://flags
  • Search for "Boundary Event Dispatch Tracks Node Removal”
  • Set to Disabled
  • Click Relaunch
• Microsoft Edge: Edge is Chromium-based and likely affected on the same major version. Try the same in edge://flags.

Revert the workaround: Set the flag back to Default (or use Reset all to default) and Relaunch.

Note about flag availability:
Chromium flags are temporary/expiring and may not be available across all Chrome/Edge channels/versions. Firefox remains the most reliable client-side workaround.

Alternative: Use a non-Chromium browser such as Mozilla Firefox.

[karthikindia]

Drag and drop is broken since the latest Chrome update.

To reproduce,

1. go to https://lab.open-roberta.org/
2. Choose any robot
3. Try to add any sensor from the left panel

This should make it obvious, that drag & drop is broken. On Safari the function still works.

This was tested on MacOS 15.7.3 (arm)

will this be fixed soon ?

[adrianosantos-art]

No Mozilla Firefox funciona bem.

[chrschng]

Is there an ETA for a fix in the Lab? Our managed Chromebooks all have been updated to Chrome 144 recently, which triggers this bug and causes quite some frustration among the kids.

[AHberta]

We don’t have a reliable ETA for a Lab fix yet, sorry. For now, please use a temporary workaround via Chrome/Chromium flags:
Open chrome://flags → search for boundary → set “Boundary Event Dispatch Tracks Node Removal” (#boundary-event-dispatch-tracks-node-removal) to Disabled → relaunch the browser.

Thanx

[schwerdti]

A tip for Microsoft Edge as the flag is not visible via edge://flags (tested with version 145.0.3800.70): You can simply use a modified Edge shortcut and share it with your users:

"C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --disable-features=BoundaryEventDispatchTracksNodeRemoval --new-window "https://lab.open-roberta.org/"

Make sure to close all Edge browser windows before using this shortcut.
This approach works equally well for Google Chrome.

[chrschng]

Our Chromebooks are centrally managed and the admin console does not allow setting experimental flags, only enterprise policies. This means we have to set this flag in each session and for every single Chromebook manually, which adds significant friction at the beginning of each course.

[gonuldagi5858-rgb]

here in the Netherlands we encounter the same problem with the chromebooks of the students. After setting up the flag the system needs to be restarted. After restart of the chromebook the setting is set to default again. so we are not able to work with google chome at all. is there any hope that this issue will be fixed soon?

[gonuldagi5858-rgb]

Also the simulation of the NAO does not work. the message "Could not connect to session server" appears. is there a workaround to let it work?

[sebastiantrella]

Drag & Drop is still broken. Hoping for a fix soon.

[AHberta]

Reproducible in recent Edge/Chrome (Chromium versions 144).

Fix in progress: Pointer → Mouse event mapping (workspace/flyout) + preventing inactive tab panes from intercepting events.
Please re-test after deployment and report back.