The Red Planet readme does indeed refer to version 1.2 or above. Red Planet, however, is Hugo's mod for Strange Adventures in Infinite Space (Weird Worlds' predecessor). You should in fact update to v1.5 if you are playing SAIS.
Of course if it is SAIS you are playing, these forums are not really relevant (being dedicated to Weird Worlds).
In either case, I recommend the
Infinite Space Federation forums for anyone interested in modding (both for Weird Worlds and for SAIS). There is quite a lot of activity in the ISF Weird Worlds modding forum, and you will learn plenty by reading through the existing threads.