I installed Ubuntu 16.04 yesterday and since then I have a problem with the mouse cursor.
It starts randomly disappearing and flickering a lot mostly when you try to close the window.
I have searched for a solution on Google and here but didn't find anything.
I had the same problem some time back when using ubuntu 14 version. You can fix it manually by going to Open System Settings > Displays. In the Displays window, you will see an Unknown monitor. Click it and disable it.
If you have 2 built in display in red and green color.. Disabling the green built in display will solve the issue.