Ravicai

I ran into the same error as this guy when I tried to play a game with my wife. We could get into the lobby, but when we tried to join each others game it gave us the "Your version is not the same..." error. Despite the fact that we did fresh installs and had exactly the same patches/mods installed. All three of the computers in my house had the same problem. Ironically, when attempting to play RA2 or Yuri with no mods, they worked just fine. Something was amiss with Mental Omega.

Well, I figured it out.

As many of you are probably aware, on certain systems the game runs more stable if you set all of the 'exe' files to 'Compatibility Mode' - Windows 98/ME. Well, if you don't have ALL of them set to this, or if some are set to 'Windows 95' you might run into problems. So you need to make sure all 'exe' files are set to 'Compatibility Mode' - Windows 98/ME.

Just in case you don't know how to do this;
1) Open 'My Computer' and locate your 'Red Alert 2' directory.
2) Sort the files by 'Type'. This should put all of the 'exe' files next to each other.
3) Right click on a 'exe' file and select 'Properties' from the submenu.
4) Click on the 'Compatibility' tab.
5) In the field 'Compatibility Mode' click the box and select 'Windows 98/ME' from the drop down menu.
6) Click 'OK'.
7) Repeat the process for EVERY 'exe' file.
NOTE: Do NOT attempt to select all 'exe' files and perform this action once. Windows will not apply this setting to all files. You need to do each file individually to ensure the settings are correct.

After I did this, all three computers in my house were able to play together. Hopefully, the situation will be the same for you. Please post and verify your results if you have had the same problem. Thanks!