After installing via CrossTie on the Overview page, apply the official patches at:
http://www.4players.de/4players.php/download_start/PC-CDROM/Download/45929.html (3189 => 3217)
1. Download the patches from the source above.
2. Mac Users: In Finder, go to "Users/YourNameHere/Library/Application Support/CrossOver( Games)/Bottles/Supreme Commander/drive_c/Program Files/THQ/Gas Powered Games/Supreme Commander/gamedata/". Open the information window for each file. Set the rights from "read only" to "read & write" if necessary.
2.1. Lion Users: To get to your Library Folder, go to your home folder, press cmd-shift-G, type in "Library" and press enter.
3. In the CrossOver Games application, go to "Run Command"
4. Select the Supreme Commander Bottle.
5. Click "Browse".
6. Go to the location where you downloaded the file to and select the "supcom_patch_3189 _to_3217 .exe" (Default download folder for Safari is "Users/YourNameHere/Downloads/").
7. Click "Run".
8. Follow the instructions.
9. If patching was successful (It can take a long time without moving progress bar), repeat steps 3 to 8 with the "supcom_patch_3217_to_3220.exe".
10. Start Supreme Commander.