Logs you out without any reason, then asks for login and fails to do it correctly. Requires re-installation, and only after it finally works. I have only 4 other add-ons, which are some of the most popular on Firefox, all of them I basically mandatory for most users. So that dumb excuse from NordVPN developers, that it is not their fault, it is some bad bad third-party add-on interfere with theirs, is kinda funny in that case. There is no bad interference and even if there is, it is your badly written code cause this problem. Happens way too often, so I've cancelled subscription.