In the Case Yelllow scenario, the AP cost for German units to convert enemy hexes is supposed to be zero, versus the default cost of 5.
This doesn't seem to happen - conversion cost remains at 5; at least with v1.06c.
Looking at the event list, the variation for Germany is supposed to be handled by event id18 (slot 17), "German Offensive Doctrine Rulevar".
This is supposed to do a ExecSetRuleVar(4,0,0) if it's the German turn and ExecSetRuleVar(4,5,0) for all other regimes, determined by a CheckTurn check which assumed that Germany is turn 0. But actually it triggers for France rather than Germany, which I assume means that France's is actually turn 0.
Obviously this is pretty fundamental for the scenario - the German advance is much slower etc etc.