This issue is seen on the servers with .net Framework 4.5.2 installed which spawns a "wisptis.exe" process which can freeze the mouse. If the process "wisptis.exe" is killed from the taskmanager using the keyboard then mouse clicks starts to work again.
This is an issue with .net Framework 4.5.2 and customer facing this issue needs to contact Microsoft. Please check the following article for more information.
https://connect.microsoft.com/VisualStudio/feedback/details/927119
Applies To
Backup Exec 2014 SP2 on Windows 2008 SP2 server.
When Backup Exec console or SGMon console is opened, the mouse clicks do not work anywhere on the server but mouse pointer can be moved. Keyboard can be used to perform all the tasks.