When I run that I get no errors and when I try to close the terminal it asks if I want to close it while mono-sgen is running.

Edit**********
Finally I got this

Last login: Sat Nov 30 14:47:25 on ttys000
CAT-cpence:~ cpence$ mono ~/Downloads/MultiMiner.app/Contents/Resources/MultiMiner.Win.exe
System.IO.DirectoryNotFoundException: Directory '/Users/cpence/Downloads/MultiMiner.app/Contents/Resources/Miners/bfgminer' not found.
  at System.IO.Directory.ValidateDirectoryListing (System.String path, System.String searchPattern, System.Boolean& stop) [0x00000] in :0
  at System.IO.Directory.GetFileSystemEntries (System.String path, System.String searchPattern, FileAttributes mask, FileAttributes attrs) [0x00000] in :0
  at System.IO.Directory.GetFiles (System.String path, System.String searchPattern) [0x00000] in :0
  at System.IO.DirectoryInfo.GetFiles (System.String searchPattern) [0x00000] in :0
  at System.IO.DirectoryInfo.GetFiles () [0x00000] in :0
  at (wrapper remoting-invoke-with-check) System.IO.DirectoryInfo:GetFiles ()
  at MultiMiner.Xgminer.Installer.DeleteFolderContents (System.String folderPath) [0x00000] in :0
  at MultiMiner.Xgminer.Installer.InstallMiner (System.String destinationFolder) [0x00000] in :0
  at MultiMiner.Win.MainForm.InstallMiner () [0x00000] in :0
  at MultiMiner.Win.MainForm.CheckAndDownloadMiners () [0x00000] in :0
  at MultiMiner.Win.MainForm.MainForm_Load (System.Object sender, System.EventArgs e) [0x00000] in :0
  at System.Windows.Forms.Form.OnLoad (System.EventArgs e) [0x00000] in :0
  at System.Windows.Forms.Form.OnLoadInternal (System.EventArgs e) [0x00000] in :0