I am almost 100 percent certain the only reason it doesn't work on net play is because the game IDs are different. Now if someone else hosts the community build with the new ID, it won't recognize it in your library because if you used my method, it still says project M thus making it unrecognizable. If you host, it will recognize your community build but their vanilla build. The thing is that both of your community builds are the same, but it is not recognized by yours/wont recognize theirs because the IDs are different. All you have to do it figure out how to make the OSX builder make the ID to what this on is now. Is there a way to change it in dolphin? I was looking in the ISO info one time and the ID was in a text box that you couldn't edit which makes me think somehow you can...?