Does the message come up if Firefox is not running, and clicking the link starts Firefox? Otherwise, I'm not sure what link would trigger that message.
For Windows 7 users, your regular release of Firefox 115 is supposed to switch to the Extended Support Release of Firefox 115 (not to Firefox 116). Many users are reporting that this is happening automatically. If your Firefox mistakenly downloaded the update for Firefox 116, you may need to delete that to get rid of the nagging. I suggest posting the problem on the Mozilla Support site. They have a team of support volunteers to troubleshoot malfunctions with your currently installed version of Firefox, while this site is focused on idea submissions for future versions of Firefox (looking ahead anywhere from 8 weeks to many months). Here's a link to the new question form (for Windows/Mac/Linux): https://mzl.la/3y1vQUQ
