Why is the “Memory” light on? Can I still arm my system?

If an alarm has occurred, you will notice that after you disarm the system, the  “Memory “ light will be on. (or on some panels, it will be the “System” light.  It is just a local notification or reminder that there was an alarm during the last armed period.   The light will clear after you arm the system again.  You can arm it with the “memory” light on.  Arm as usual.  Check your user manual.