Does it work on TB 78.11.0?

[praveen2600]

Even after following every step, this is not working for me. Is it supported on TB 78.11.0?

[KivalM]

Have you enabled the customization option in thunderbird?
You'll need to enable the toolkit.legacyUserProfileCustomizations.stylesheets setting in Config Editor.

How to access the config editor:
https://support.mozilla.org/en-US/kb/config-editor

[smac89]

Works in TB 91 on Linux with KDE Desktop

[sg6]

FYI, for everybody facing the same problem - please follow the steps of @egggod and do not miss out that part of the README:

If your profile is located in a different directory, you can find it by going in Thunderbird's preferences (Tools->Options->Advanced). After that, click the 'Config Editor' button, accept the warning and then search for directory. Your directory should be the value of the parameter mail.server.server1.directory. This is the path where you should extract the chrome folder.

It helped me, it's now working