why? perhaps the issues that make you think you need to go back can be fixed.

Just interested in going back to earlier version. The automatic update on 12/20 created some issues with response time and I want to revert to earlier version to see if it fixes problem. Might even go back to 68 if needed. Want to make sure I don't lose my emails etc.

AFAIK there is nothing in the list of bugs fixed in https://mzl.la/3n0GLFf that would make Thunderbird slow. Suggest you describe exactly what you mean by slower "response time".

this is on my wife's computer. She does not like the latest version and wants it back to earlier. I have no interest in trying to find a solution. Just want to move it back to earlier version to make her happy. Otherwise, she will not be happy!

TB = Thunderbird.

• user may also need to Disable AV/FW/SS software, OR enable+add+allow EXCEPTIONS in it. some AV/SS creates insecure proxy/gateway for scanning/checking emails, but there are other secure way to scan/check emails.

• if that does not solve, then see below.

• please, you MUST first make backup/copy of ALL sub-folders & files under this location, copy into Desktop: "%APPDATA%\Thunderbird\Profiles\" that is usually located here: "C:\Users\<YourWindowsUserName>\AppData\Roaming\Thunderbird\Profiles\"

that ...\Thunderbird\Profiles\ folder contains multiple sub-folders , those sub-folders are various TB profile folders , a TB profile folder looks like this : "xxxxxxxx.profile-name" ( where x in xxxxxxxx is random alphanumeric characters/letters/numbers, etc ) ( the "xxxxxxxx" is profile-folder-ID part , and "profile-name" is profile's name part )

• in your case, one of the TB-profile (sub-folder) is used by TB 78.6.0, and the other TB-profile (sub-folder) is used by older 78.5.1

• How to find out which TB-profile is used by which VERSION of TB ?

• run/go into current TB (78.6.0) > main menu > Help > Troubleshooting information > about:profiles > Root directory > write down FULL PATH of root directory. the last sub-folder it shows, should be same as what you have seen earlier inside ...\Thunderbird\Profiles\ folder. so the last folder shown in TB v78.6.0's Root directory line, is used by TB v78.6.0, we will call it TB-profile-name-78-6-0, so, other sub-folder has to be used by 78.5.1 , we will call it old-TB-profile-name-78-5-1.

• uninstall TB, (do not delete profile).

• download older TB , see below italic line. ( older TB can be downloaded from a linked page, that link is shown here , then press Ctrl+F to find "Download Thunderbird Installers" link )

• install older TB 78.5.1 , (make sure to NOT SELECT the option to run TB immediately after installation).

• run only ONCE below (any one) command (out of below FOUR commands)

• start Windows "Command-Prompt" , & run only ONCE below (any one) command in Windows "Command-Prompt": • if you installed v78.5.1 TB (64bit), then run this it with below command: "C:\Program Files\Mozilla Thunderbird\thunderbird.exe" --allow-downgrade -p "%APPDATA%\Thunderbird\Profiles\old-TB-profile-name-78-5-1" (above line is a command-line) • if you installed v78.5.1 TB 32bit, then run below command inside Command-Prompt: "C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe" --allow-downgrade -p "%APPDATA%\Thunderbird\Profiles\old-TB-profile-name-78-5-1" • if you want to start 64bit TB from Windows-"Run"-box, then use below command: "C:\Program Files\Mozilla Thunderbird\thunderbird.exe" --allow-downgrade -p "C:\Users\<YourWindowsUserName>AppData\Roaming\Thunderbird\Profiles\old-TB-profile-name-78-5-1" • if you want to start 32bit TB from Windows-"Run" , then use below command: "C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe" --allow-downgrade -p "C:\Users\<YourWindowsUserName>AppData\Roaming\Thunderbird\Profiles\old-TB-profile-name-78-5-1"

• if TB v78.5.1 shows all older setting+info correctly, then downgrade succeeded & that profile-name is the correct one.

• so to KEEP ON USING that profile, use ONE of this command (out of FOUR command) only ONCE:

• if you installed v78.5.1 TB (64bit), then run this it with below command: "C:\Program Files\Mozilla Thunderbird\thunderbird.exe" -P (above line is a command-line) • if you installed v78.5.1 TB 32bit, then run below command inside Command-Prompt: "C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe" -P • if you want to start 64bit TB from Windows-"Run"-box, then use below command: "C:\Program Files\Mozilla Thunderbird\thunderbird.exe" -P • if you want to start 32bit TB from Windows-"Run" , then use below command: "C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe" -P

• and then TB profile choosing windows will appear , Choose the profile-name part for the old-TB-profile-name-78-5-1 profile, and also select the option "Continue to use this profile",etc.

• once you done above step, then you don't need to use "Command-Prompt" or "Run" box anymore, you can use Thunderbird = TB software icon to start the TB.

EXTRA INFO for other/related problems: • Disabled auto-update of TB : inside the linked page , click on the topside 1st link to goto the auto-update disable instruction page into another website. • Regain old data(in Windows, by using: downgrade process, or second-TB, or manual file-transfer,etc). • Downgrade TB in macOS: downgrade by using second-TB, upgrade TB. • ATT-Yahoo related settings for TB. • Yahoo related settings for TB. • Microsoft related settings for TB. • Convert mab based Address-Book into other format.

Thanks very much. That is what I was looking for. I will do it later today.

this is on my wife's computer. She does not like the latest version and wants it back to earlier. I have no interest in trying to find a solution. Just want to move it back to earlier version to make her happy. Otherwise, she will not be happy!

Just be aware that it is very unlikely that you will get through the process of "downgrading" without some sort of issue, either now or in the future. I for one am over spending my time helping people make their systems less secure and helping them potentially loose their data without reason. Aesthetics are not a reason in my book.

Keeping my wife happy is a very good reason! Downgrade went fine.