This error indicates that you have a sensor triggered in a zone that is preventing the system from arming. You can switch the zone off to bypass the zone & then you will be able to arm your system. This can be done on the web portal, the app or on the touch screen.
On the Web Portal, in the zones section, scroll down and click the link that says Manage Zones. From there you can toggle the troubled glass zone to the off position.
In the App, you can scroll to the bottom of the screen to access your zones & toggle the troubled glass zone off from the following screen.
You could also change this on the TouchPad in the Security section. Your zones will be displayed on the right hand side & you can turn the troubled glass zone off from there.