+++ This bug was initially created as a clone of Bug #1400204 +++

Thunderbird 91.0.1 MAC

Steps to reproduce:

1. Set up a master password and multiple accounts, including WebDAV calendars
2. Restart the mail client

Actual results:

TB prompts for a master password in a dialog. Before being able to type, the dialog disappears another master password dialog appears (potentially multiple times).
Even in safe mode the problem persists.
Problem occurs no matter whether multiple windows are open.

Severity: High as TB is unusable right now

I do have pending messages in my outbox and the dialog that ask me to send out these messages pops up first, but then gets hidden by the password windows.

Is there a way to force TB to have the password dialogs as "really independent" windows? It seems that there was a change some releases ago which now make these dialogs part of the main window. If they were completely independent, maybe we can at least make them accessible as a workaround.

Resetting priority and severity so that the bug can be triaged by the Thunderbird folks.

Most likely this is a duplicate of Bug 1721084, but I'm not sure if Thunderbird uses the antitracking component or not...

BP, I'm not familiar with Thunderbird so I don't know if you're able to access something like about:config, but if you are able then comment 65 on the previously mentioned bug mentions a workaround:

If you're not on Nightly, a temporary workaround is to disable tracker purging by setting privacy.purge_trackers.enabled to false in about:config. Make sure to enable it again once the issue is fixed.

I think the hang aspect is not caused bug 1400204 nor bug Bug 1721084. However, these may be causes of multiple prompts.

Mac hangs are related to factors described at bug 1609234

There seems to be some confusion here whether this is related to the Firefox multiple-primary password prompts bug (Bug 1721084). If it is related at all, that fix should at least improve things. BP or :wsmwk, can you check if the workaround in comment 3 helps (or if the problem persists in Nightly?)

If not, then I think we are talking about something TB-specific.

I can imagine that this is in fact related to bug 1609234.
:sfoster my problem is that I cannot click any window, so cannot access about:config. Is there a way to change the setting through one of the files in the profile folder?
Also, given that this problem happened on a production system, I am hesitant to switch to Nightly...

Tiny update:
in prefs.js, I found
user_pref("privacy.purge_trackers.date_in_cookie_database", "0");
user_pref("privacy.purge_trackers.last_purge", "1629368683012");

and added

user_pref("privacy.purge_trackers", false);

However, this does not change anything.

To explain the problem a bit more detailed: When TB starts, the prompts appear one after another, at the same time, I see the MacOS spinning ball until the last dialog has appeared. It seems to be the case that i can access the TB menu bar and select certain items (e.g. trigger to open the settings or accounts tab or create a new appointment, but NOT start a new message).
However, I cannot click, select, ... any item in the main TB window / any tab. Only in a new window (e.g. new appointment), I can manipulate any content.
The task bar indicates "mail_addres@server: connected to imap.provider.net..."
When trying to quit TB, it crashes (see crash report, e.g. with TelemetrySessionId: 6fcd6ca1-82f6-244f-9c6f-328536ead79d).

yet another update: I left TB open over night (in standby) and when I returned, the "online again - send remaining messages?" popup was open. I disabled this reminder (would be great to find this option somewhere again in about:config) and restarted TB. As this dialog does not show up any more, I hoped to solve the problem, but it persists. So now it seems to be related to the password popups only.

I believe this will end up being a duplicate of bug 1712980

Yes, this looks like the same issue. not sure how I can help to fix this, but it clealy should be fixed soon.

BP, this workaround helped me for the time being: https://bugzilla.mozilla.org/show_bug.cgai?id=1712980#c2

@:alberts Indeed, the workaround explained at https://bugzilla.mozilla.org/show_bug.cgi?id=1712980#c2 does help - but of course it would be nice to get this fixed. Moving the remaining discussion to that bug report...