Well monthly patch, november in this case, is a must (without it your client wont connect to the server ip), I think it doesnt matter if you used the hero patcher before that, but its best not to. full installer + november patch after should work too technically.
Are you 2 on a network in the same place? You could try sharing your working folder to your girlfriend, she could make an exact copy of yours.
Also, make sure you have enough free space on your computer, programs often crash when the computer doesnt have enough temporary memory.
Can you copy the content of your data.ini ?
Hope this helps