Thunderbird freezes after startup. I tried restarting, Troubleshoot Mode, and both “default” and “default-esr” profiles, but the issue remains. Please advise how to fix this without losing my emails. This is affecting my work and needs urgent resolution.

Additional details: * Operating system: Windows (please specify your Windows version if known) * The issue started on August 25, 2026. * Thunderbird becomes unresponsive shortly after startup. * A “System Integration” prompt appears before Thunderbird becomes unresponsive. * I cannot click any buttons once Thunderbird becomes unresponsive. * I tested both available profiles (“default” and “default-esr”) using the Profile Manager, but the same issue occurred with both profiles. * I also started Thunderbird in Troubleshoot Mode with all add-ons disabled, but the issue still occurred. * I can force-close Thunderbird through Windows when it becomes unresponsive. * I have not deleted or modified any Thunderbird profile files because I want to avoid losing existing email data. * The profile containing my email data appears to be “default-esr”. I would appreciate any guidance on how to identify the cause of this issue and restore Thunderbird without losing my existing emails.