I've done a bit of research and contrary to what the UMP documentation says from Marshall, I believe this to be fixable within a mod. The YRO files are normal mix files and they get loaded first out of any mix file. That means that any file within them is superseded by an identical file name in a mix loaded later in the order (both expand and ecache files fit this description). Thus a mod can replace these maps with new versions that the official versions cannot overwrite, but that won't be playable until the YRO files are installed because the .pkt file needed for each map is loaded from them.
That's good to know. The UMP does say that you can include the maps in an expand mix though (although I never actually tested this, forgetting about the YRO format at the time). This is in the 'extras' section.
The UMP should, then, include the fixed map pack maps. Problem is I can't extract stuff from a YRO using XCC Mixer. Perhaps DCoder's new tool will do the job...
Ever wondered what the hell is going on?
Believe me friend you're not the only one.
--Lysdexia
Check out Launch Base for RA2/YR - http://marshall.strategy-x.com
Also home to the Purple Alert mod, 1.002 UMP, and the YR Playlist Manager.
Really? I extracted them ages ago using XCC (though probably an older version of what you used since i haven't updated in ages). Please see the attached.