Moving alarms in the chart

 
I have two installations on two laptops. Both MT5 5.0 3091
In one of them I can click on the alarms in the chart, move them or delete or change them using the right mouse button.
In the other one I cannot select them.
Where can to set this ?
 
Possibly too many dead alarms in the Alarms tab. Go and right-click → delete them.