Yes, they do expire. When you purchase a license key for the BYOL licensing system you purchase it for a certain amount of time. The choices are 1, 2, 3, 4, or 5 years. At the end of that time, when the license key reaches it end date and expires, it will disappear off your server automatically. If the last license key on your Access Server expires, it reverts back to its demonstration mode where only 2 simultaneous connections are allowed. A few weeks before the license key expires, you will receive emails from our automated licensing system on the email address of your account on our main website where license keys can be purchased, to remind you that the key is about to expire, and to ask that you renew it.
If you have in the past purchased a perpetual license key, then read the section below if you are having a problem with such a license key.