Compile error little sub

Hello all,
i want to use vba compiler and protection but when he refused to compile the code… The compiler give me that code :

“Synthax error, line 1,16” (see screenshot)

My sub is very simple :

sub protect_as ()
ActiveSheet.protect ("")
end sub

Do you have some idea ? thank you

my excel is 2016 version and window 10 64 family version.

ActiveSheet is not defined by default. You have to specify Application.ActiveSheet, see user guide: