In the development phase between gretl 1.9.5 and the soon to be released gretl 1.9.6 we have tightened up on some aspects of scripting syntax. (The intent is to avoid obscure errors.)
One point has already been noted: we no longer accept stray semicolons at the end of lines. Here's another: if you're defining a new variable of type "list" in a script, you must use the type-name, for example list L = x1 x2 x3 (as specified in the Gretl User's Guide). If you try to make L a list implicitly, as in L = x1 x2 x3 You'll get a syntax error. (But if "L" is already the name of a list at the time the above command is issued, that's OK.) This is because the syntax whereby a space between terms means list-concatenation of series is very special, and we want to allow it only if we know in advance that the left-hand side variable in a gretl formula is supposed to be a list. Allin Cottrell