We have/had some rare exception when the application run and the pc goes into power save mode ore the user disconnects/reconnects Remote Desktop-Connection.
We have one exception trace and this point to the problem that the elpack-implementation don't check if a monitor is pressend at the current point.
We change the line
LNMon := Screen.MonitorFromPoint(q).MonitorNum;
Mon := Screen.MonitorFromPoint(q);
if not Assigned(Mon) then
LNMon := Mon.MonitorNum;
to handle this very special situation where the amount of monitors changes.