User Activity Monitor : Monitoring Settings : Rules : Creating rules : What if there is nothing to record?
  
What if there is nothing to record?
The triggering of the rule does not lead to the creation of a record in the UAM Log if the DeviceLock Service has not managed to register any user actions for the entire duration of the recording. This situation is considered in more detail in the following table.
 
Rule is configured to capture
What happened during recording
Screen only
DeviceLock Service did not take any screenshots.
Keyboard Input only
DeviceLock Service did not register a single keystroke.
Screen and Keyboard Input
DeviceLock Service did not take any screenshots and did not register a single keystroke.
In all cases listed in the table, a record is not created in the UAM Log.