
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. Another program on the system is blocking the link from opening and needs to be removed or modified.If this does not work, then chances are the issue has been generated by one of three other possible causes: Steps to do this for the more popular browsers are available at these URLs:įor Chrome: /chrome/answer/95417įor Firefox: /en-US/kb/make-firefox-your-default-browserįor Edge: /en-us/instantanswers/5b81713b-5ab4-4462-a002-93e8d3d34c06/make-microsoft-edge-your-default-browser To fix this, you need to reset your browser default designation on the computer. 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.
