Usually if such a error appears it is the mistake of the one who made the makefile.
I will tell you what ***missing seperator means
*** means fatal error(that is the make can't continue and exits)
seperator is any of the seperators (:, =, TAB characters, etc) is missing.make looks for various kinds of separators to help it decide what kind of commandline it's seeing.
So I think that you understood the meaning of the missing seperator one.
The usual approach to solve the problem is by pressing Tab at the line number you mentioned.