Reportedly this crashes if run against 1.3.2, which is surprising given how little it changes.

Only thing I can think of is the the observe mode button that was added to menubar.gui in 1.4 is trying to load graphics that don't exist on 1.3.2.

So, if you delete lines 3166-3196 from interfaces\menubar.gui in the mod, everything might work okay. If not have a look if there is anything in the error.log that looks relevant.