
Thunderbird Nightly - Experience the newest innovations with nightly releases (for those that want to work with breakages).Thunderbird Beta - Cutting edge features with relatively-good stability.Install the thunderbird package, with a language pack if required. 5.6 Outlook 365 SMTP fails to authenticate with OAuth2 authentication.5.5 Authentication failure while connecting to server error when using OAuth2 with G Suite account.5.4 LC_TIME environment variable not respected.5.3 Thunderbird UI freezes when receiving a new message.5.2 Error: Incoming server already exists.4.3 Plain text mode and font uniformity.Specifically, look for the instructions found beneath the sub-headlines "Check that no application is specified for the HTTP content type," "Check for an incorrect preference" and "Check for interference from an extension. Instructions for working through each of these potential situations can be found at the link mentioned above: /en-US/kb/hyperlinks-in-messages-not-working A setting in Thunderbird is blocking the URL from opening and needs to be changed or updated.A recently installed add-on or extension in your default browser is blocking the URLs from opening and needs to be removed or modified or.This could be anything from an antivirus to a new piece of software that was recently installed but conflicts with Thunderbird.


This means that when you click on a URL in your email, the Thunderbird program no longer knows where to direct that link (since no default browser has been designated in Windows) and as a result the link doesn't work when clicked. Per the information on this forum page, the most common cause of this issue is that your version of Windows has somehow lost its default browser designation. The Thunderbird Support Forum itself does host a page devoted exclusively to the problem listed above, found here: /en-US/kb/hyperlinks-in-messages-not-working. To do this, visit this URL and then click on the "Ask Now" button on the right of the page: /en-US/questions/new/thunderbird. If you cannot find an answer to your question easily on the support forum, then it's suggested you create an account with Mozilla and post your question publicly to the forum, which (believe it or not) often yields very good results.
