Just as Questions states. I open a project in unity, click file, build settings, switch to Mac OS X on the pull down window and click build. Note that the same occurs for windows after the first build for windows succeeded. Also note that between the first build and second attempt, simple things in project were changed, such as extending an array in a script and color changes but little else. After about 5 mins the progress bar fills the whole way but at the end a windows error sounds and no message pops up. No files are created in the file location. I have redowloaded Unity several times, both the 2017.3.0f3 and the 5.6 versions of the engine and try it each time. Every time is the same. Please help quickly as I need the build in the next few days. Tomorrow if possible.
I have fixed the issue. I rebuilt the whole thing from scratch, using prefabs from the previous game. I did some fixing as well and it now builds. I have no idea what did the trick. I sent a bug report in and they believe that it was a error that I was getting in console relating to one of my scripts that told me I could not initialize a variable at the same time I declared it. However, that error was present on the first successful build I did so still a bit of a mystery.