Does acknowledge work when logged in as an administrator?
The Acknowledge All Visible Alarms function attempt to acknowledge by writing FALSE to the Alarm Global Properties:IsAlarmUnack_Descendants property located on:
a) all objects having display elements inserted in the graphic display
b) children to objects identified by a)
c) the object owning the graphic display
d) children to objects identified by c)
a) is obvious from the name of the function, but b) c) and d) is probably lesser known.
Acknowledge may fail if the user lacks "Operate" permission one or more objects in the hierarchy of descendants objects identified by a, b, c and d.