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Unwanted automatic launch of 2 instances of Thunderbird

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  • Last reply by Robert12

Robert12
Robert12
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Hi All, Since update of Thunderbird to version 115.2.3 (64-bit), I keep getting 2 instances of Thunderbird that vie with each other to retrieve IMAP messages. I keep getting error messages until I close one of the 2 instances (Thunderbird windows). I found a workaround. If I click "Help | Troubleshooting information" and press "Clear startup cache…", then "Restart", Thunderbird restarts normally with only one instance. But this is only temporary. It happens only once after I have cleared the startup cache and restarted Thunderbird. When I restart Thunderbird later, it systematically launches with 2 instances. Thank you for any more permanent solution.

Hi All, Since update of Thunderbird to version 115.2.3 (64-bit), I keep getting 2 instances of Thunderbird that vie with each other to retrieve IMAP messages. I keep getting error messages until I close one of the 2 instances (Thunderbird windows). I found a workaround. If I click "Help | Troubleshooting information" and press "Clear startup cache…", then "Restart", Thunderbird restarts normally with only one instance. But this is only temporary. It happens only once after I have cleared the startup cache and restarted Thunderbird. When I restart Thunderbird later, it systematically launches with 2 instances. Thank you for any more permanent solution.

Chosen solution

I found the solution myself. The command-line launching Thunderbird from the Windows 10 taskbar had extra parameters linked to outlook.com. I removed these extra parameters. It did the trick. Only one instance of Thunderbird is now launching through that taskbar icon. Problem solved!

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Robert12
Robert12 Question owner
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Chosen Solution

I found the solution myself. The command-line launching Thunderbird from the Windows 10 taskbar had extra parameters linked to outlook.com. I removed these extra parameters. It did the trick. Only one instance of Thunderbird is now launching through that taskbar icon. Problem solved!

Wayne Mery
Wayne Mery
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Robert12 said
I found the solution myself. The command-line launching Thunderbird from the Windows 10 taskbar had extra parameters linked to outlook.com. I removed these extra parameters.

So glad you solved it.

Please share the exact parameters that were causing the problem. Thanks

Robert12
Robert12 Question owner
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I cannot remember exactly. Something like -IMAP /office365.com or -IMAP /mail.outlook.com had been appended to "C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe"