Thunderbird discovered that yahoo have changed their mail server’s POP3 behaviour, meaning you can’t leave mail on their server and download it locally. So it pops up the following message box:
This message box is app-modal. You can’t just fix the problem, you’ve got to take notes (a screenshot suffices) and then fix the problem. A bunch of faffing around, when it could have just said “Do you want your Server Settings automatically changed so that your mail can be fetched? Yes/No”. Or you could have this pile of technical information in a non-modal dialog box, and bring up the settings dialog for the user to solve the problem. Or just have this pile of technical information in a non-modal dialog box, so a screenshot isn’t necessary.
Or you could just make people angry, that works too.
Yeah, this sort of thing completely bewilders non-techy users, and is an example of where open source projects sometimes misfire (though of course commercial software is prone to do it too).