2075935 - Thunderbird should recover gracefully from a failed or stalled session restore

Status: UNCONFIRMED

(Thunderbird :: Untriaged, enhancement)

Description

[Ignazio]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:140.0) Gecko/20100101 Firefox/140.0

Steps to reproduce

While investigating the startup hang reported in Bug 2071951, Thunderbird repeatedly became unresponsive while restoring a previously saved session.
Renaming the saved session.json allowed Thunderbird to start normally again with the same profile.
This enhancement request is separate from the underlying defect reported in Bug 2071951.

Actual results

When restoration of the saved session failed, Thunderbird remained unresponsive and could not be used.
On subsequent starts, Thunderbird attempted to restore the same saved session again and became unresponsive again.
Manual intervention was required to make Thunderbird usable again.
For the user, this situation can be particularly stressful because Thunderbird appears to be unusable, while there is no clear indication of what has happened or how to recover from the situation.

Expected results

If restoration of a previous session cannot be completed successfully, Thunderbird should recover in a way that keeps the application usable.
The user should receive a clear and understandable message explaining that the previous session could not be restored, while reassuring them that their accounts and messages are not affected.
Information about the failed session should remain available for diagnostic purposes so that the underlying cause can still be investigated.
The goal is that a problem with session restoration should not leave the user repeatedly unable to start and use Thunderbird.
This recovery behavior is intended as a safeguard for the user and does not replace identifying and fixing the underlying cause of the session restoration failure.