Everytime I try to open local.mix (from within ra2.mix), I can't explore it, which means I can't extract rules.ini, art.ini, etc... Instead, it says it's a text file instead of a mix file. On the right pane, it shows some contents that look like it comes from an INI file and, when I scroll down, I see some parts of rules.ini and art.ini

I have both RA2 and Yuri's revenge, both upgraded with the latest patches, if that matters.

Any help on this matter is appreciated.