2060748 - Dragging and drop a file from a message to a folder or desktop stops with a "Unspecified error"

Status: ASSIGNED

(Thunderbird :: General, defect, P1)

Description

[Vasilis Lourdas]

Attachment: 2026-08-05_090854_1V.png

Steps to reproduce:

I try to drag and drop a file from a message inside my Local folders to the desktop.

Actual results:

I get a Unspecified error window and the file is not saved.

Expected results:

The file should be saved in the destination folder.
Saving the file manually by right clicking and choosing Save as the file is saved without an issue.

The version is 153.0.2 in Windows 11.

Comment 1

[Vasilis Lourdas]

The weird part is that I tried this in 2 other PCs with Windows 11 and TB upgraded to 153.0.2 and the problem does not occur in their installation. But since there's already another bug reported with the same issue, I guess it must be a regression.

Comment 6

[alexey]

I can confirm this issue on Thunderbird 153.0.2 ESR (Windows 10).

An additional observation:

Drag & drop fails when performed normally.
Drag & drop works correctly if I hold the Ctrl key while dragging (the cursor shows the "+" copy indicator).

"Save As..." also works correctly.

This may indicate that the issue is related to the default drag-and-drop effect, while the explicit Copy (Ctrl) operation succeeds.

Comment 7

[Vasilis Lourdas]

(In reply to alexey from comment #6)

I can confirm this issue on Thunderbird 153.0.2 ESR (Windows 10).

An additional observation:

Drag & drop fails when performed normally.
Drag & drop works correctly if I hold the Ctrl key while dragging (the cursor shows the "+" copy indicator).

"Save As..." also works correctly.

This may indicate that the issue is related to the default drag-and-drop effect, while the explicit Copy (Ctrl) operation succeeds.

I confirm the above behaviour with the Ctrl key and the manual Save as... action.

Comment 8

[Axel König]

Hallo, bin hier neu hier und kein Experte. Eine KI hat mir bei der Fehlerbehebung "Drag-and-Drop" funktioniert nicht nach Thunderbird-Updat 153.0.2 ESR (Windows 11) geholfen: [Bug 2060748] Dragging and drop a file from a message to a folder or desktop stops with a Unspecified error window. Die Antwort von Wassilis Lourdas kann ich bestätigen: Sobald ich während dem Maus-Ziehen Strg gedrückt halte, kann ich eine Mail in den Explorer ziehen. Habe das mit einigen Mails und in einige Ordner probiert. Einschränkung ist, dass das offensichtlich nicht immer funktioniert und der Fehlerbericht bei gleicher Handhabung geziegt wird: "Unbekannter Fehler". Optisch sieht das auf dem Bildschirm so aus: Linke Hälfte des Bildschirms Thunderbird, rechte Hälfte Explorer. Mit der Maus und Strg-Taste gedrückt ziehe ich eine Mail nach rechts. Sobald dieser Vorgang über Thunderbird geschieht, erscheint dieses "eingeschränkte Halteverbot"-Symbol (roter Balken diagonal durch roten Kreis), über Explorer dann "+" - allerdings geht das, dann geht das mal wieder nicht.

Comment 9

[Axel König]

(In reply to Axel König from comment #8)

Hallo, bin hier neu hier und kein Experte. Eine KI hat mir bei der Fehlerbehebung "Drag-and-Drop" funktioniert nicht nach Thunderbird-Updat 153.0.2 ESR (Windows 11) geholfen: [Bug 2060748] Dragging and drop a file from a message to a folder or desktop stops with a Unspecified error window. Die Antwort von Wassilis Lourdas kann ich bestätigen: Sobald ich während dem Maus-Ziehen Strg gedrückt halte, kann ich eine Mail in den Explorer ziehen. Habe das mit einigen Mails und in einige Ordner probiert. Einschränkung ist, dass das offensichtlich nicht immer funktioniert und der Fehlerbericht bei gleicher Handhabung geziegt wird: "Unbekannter Fehler". Optisch sieht das auf dem Bildschirm so aus: Linke Hälfte des Bildschirms Thunderbird, rechte Hälfte Explorer. Mit der Maus und Strg-Taste gedrückt ziehe ich eine Mail nach rechts. Sobald dieser Vorgang über Thunderbird geschieht, erscheint dieses "eingeschränkte Halteverbot"-Symbol (roter Balken diagonal durch roten Kreis), über Explorer dann "+" - allerdings geht das, dann geht das mal wieder nicht.

Ich sehe, dass der Text von vorhin völlig verzerrt dargestellt wird. Das kann man nicht lesen.

Comment 10

[mt_]

I can reproduce the behavior in 153.0.2ESR on windows 11 and on OpenSUSE SLED. Drag and drop works on 153.0ESR flawlessly however.(In reply to Vasilis Lourdas from comment #7)

(In reply to alexey from comment #6)

I can confirm this issue on Thunderbird 153.0.2 ESR (Windows 10).

An additional observation:

Drag & drop fails when performed normally.
Drag & drop works correctly if I hold the Ctrl key while dragging (the cursor shows the "+" copy indicator).

"Save As..." also works correctly.

This may indicate that the issue is related to the default drag-and-drop effect, while the explicit Copy (Ctrl) operation succeeds.

I confirm the above behaviour with the Ctrl key and the manual Save as... action.

I can confirm the workaround holding down CTRL works with Windows 11 aswell.

I can also confirm it does NOT work with OpenSUSE SLED 15.7 (using KDE) and Thunderbird 153.0.2 ESR.

As soon as the mouse cursor exits the window, it straight up crashes and the crash report window opens up.
I have filled out the form and sent it in, referencing this bug ( 2060748 ) in the description.

We are currently preparing our enterprise configurationset for the 153ESR, so we test both windows and linux.
From what we could see is that this bug only appears on 153.0.2ESR, no version prior (140.0.1ESR upwards to 153.0.1ESR) has had an issue.

Interestingly under Linux (OpenSUSE), the 153.0.1ESR did actually log error messages in the console whenever a drag and drop operation was occuring when the mouse cursor was moved outside of Thunderbird, logging the following code:
Uncaught NS_ERROR_FAILURE: Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsITransferable.getTransferData] getFlavorData chrome://messenger/content/about3Pane.js:5601 43 about3Pane.js:5601:20 getFlavorData chrome://messenger/content/about3Pane.js:5601

Comment 12

[Hartmut Welpmann [:welpy-cw]]

Regression windows:
https://hg-edge.mozilla.org/comm-central/pushloghtml?fromchange=a04353d1b298e9e31e7973de543a926880aff523&tochange=b41657cdea2585e232d64623be411086ab686018
https://hg-edge.mozilla.org/mozilla-central/pushloghtml?fromchange=30ee6b638c6a45ca3622dabce862c6de04126786&tochange=e27ed214afc885ba37c203ec0fafac8be01fd237

On Linux it's even worse, dragging a message simply crashes the application. Here's the AI-assisted assessment:

Root cause: upstream regression from Bug 2054665 (changeset 91f8065a47c7, uplifted to mozilla-esr153 2026-07-31 → in TB 153.0.2), confirmed by mozregression on Thunderbird/Linux.

Bug 2054665 changed nsBaseDragSession::InvokeDragSession (widget/nsBaseDragService.cpp) to SetDataPrincipal(mTriggeringPrincipal) instead of mSourceNode->NodePrincipal(). For chrome-initiated drags mTriggeringPrincipal is null by design, so the transferable's data principal becomes null. The thread pane is chrome → message drags fail:

• Linux: crash when the cursor leaves the window (null loading principal in CreateTempFile).
• Windows: NS_ERROR_FAILURE from nsITransferable.getTransferData in getFlavorData → "Unspecified error".

Suggested fix upstream (Core :: Widget): fall back to mSourceNode->NodePrincipal() when mTriggeringPrincipal is null; uplift to ESR153.

Comment 16

[Toby Pilling [:tobyp]]

Thanks so much Hartmut - I had just started looking into this myself.

Have you already..Suggested fix upstream somewhere?

Comment 17

[Toby Pilling [:tobyp]]

Ok yes I see that you NI'd Leo. Thanks!

Comment 18

[Hartmut Welpmann [:welpy-cw]]

Yeah, I am not sure there's a sensible workaround for this possible in Thunderbird code. Also might be even S2 for the crash on Linux.

Comment 19

[Corey Bryant]

We could ask for a backout of the Firefox change for now. It's not published in a Firefox 153esr release. And it's not in Firefox 153 Release channel. I'll mention it the #release-coordination slack.

Comment 20

[Leo Tenenbaum [:ltenenbaum]]

Thanks! I think it would be fine to back it out for now - it's a security bug, but not so severe. I'm hoping something like this WIP patch will work.

Comment 21

[Leo Tenenbaum [:ltenenbaum]]

Attachment: Bug 2060748 - Add ifdef MOZ_THUNDERBIRD workaround for drag+drop regression. r=edgar

Comment 22

[Corey Bryant]

Thanks Leo!

Comment 23

[Leo Tenenbaum [:ltenenbaum]]

Attachment: Bug 2060748 - Get principal from dragContent if it doesn't come from a remote process. r=edgar