I cant create a mask using comand Ctrl+Alt+M

[Dmitriy_Fedotov]

, only by using mouse or menu. What can be the reason of it ?

[tank666]

Option key makes a copy of text layer

Most likely you have some kind of application installed (for example, Punto Switcher or others) that intercepts shortcuts. Disable such an application or change its shortcuts, and everything will work as expected.