The errror message should point to a filename and a line number. If the filename is the same file that you added the "INCLUDE" statement to, and the line number points to that statement as well, then it may just be that you need to quote the pathname. So instead of this:
You would use this instead:
On the other hand, if the error message is pointing to the filename of the file you included, then it means you already included the file properly but that there is an error in that other file. You would need to find the line number in that other file and we could look there to see what the problem is.