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Thunderbird keeps "not responding" off and on for up to three hours

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  • Last reply by Wayne Mery

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Whenever I launch Thunderbird (Windows 10 64 bit computer) the program keeps saying "not responding" for about a minute, then unlocks for about three seconds then "not responding" again for about a minute and does this over and over for at least 30 minutes. If I haven't opened Thunderbird for a few days and have 10 to 20 emails to download it has taken up to three hours to download the emails and quit "not responding" off and on until it finally runs correctly. I can't use the program until it finally quits. It shouldn't take three hours to check my email. Can you help?

Whenever I launch Thunderbird (Windows 10 64 bit computer) the program keeps saying "not responding" for about a minute, then unlocks for about three seconds then "not responding" again for about a minute and does this over and over for at least 30 minutes. If I haven't opened Thunderbird for a few days and have 10 to 20 emails to download it has taken up to three hours to download the emails and quit "not responding" off and on until it finally runs correctly. I can't use the program until it finally quits. It shouldn't take three hours to check my email. Can you help?

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1. Start Windows in safe mode with networking enabled - https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode 2. Still In Windows safe mode, start Thunderbird in safe mode - https://support.mozilla.org/kb/safe-mode-thunderbird

Does problem go away?

- If no, then cause is either: bug in Thunderbird, a setting, file or folder (something) in your Thunderbird profile, your mail provider. Please attach to the bug report or support topic a file created from Help | Troubleshooting | copy text to clipboard

- If yes, the problem is gone, then (still in Windows safe mode) ... start Thunderbird normally -- If problem is still gone, then cause is likely a program loaded during windows startup. Possibilities include: antivirus software (AV), virus/malware, background downloads such as Windows or other program updates, to name a few. For AV information see https://wiki.mozilla.org/Thunderbird:Testing:Antivirus_Related_Performance_Issues -- If problem came back, then cause is likely a Thunderbird add-on - eliminate them by disabling add-ons one at a time in Tools | add-ons | extensions and restart Thunderbird after disabling (if you have many add-ons, try disabling half of them at a time)

- If results are unclear ... possibilities include temporary conditions such as contention from other running programs, downloads related to windows update, ...

Please let us know your findings.