unknown commands group layer

[ITEC54]

Good morning to all,
I'd need to ask if something like this ever happened to you.
in the autocad interface 2015, all commands work except the layer tools, giving me unknown commands.
Do you know how to help me?
Thank you very much in advance

 

[dieva]

What do you mean by layer tool? if you type on the command line for example islandy or _layiso what happens?