Resetting Firefox will not delete bookmarks, or saved passwords, but one cannot take guarantee of this. It might be best to back up your Mozilla Firefox bookmarks first and then implement the following steps:
If the error persists, then you need to call mozilla firefox tech support phone number to speak with the professional experts who are there to help you in fixing the issue.
Visit here:
Hi.....
Reset Mozilla Firefox to default settings (Step-by-Step Guide) If Firefox starts to act slow, crashes, or displays unwanted advertisements, resetting it to the default settings can help. The reset feature fixes many issues by restoring Firefox to its factory default state while saving your essential information like bookmarks and open tabs.
you can get the more information then click here Netgear Nighthawk