Anytime I try to install one of the patches, an error message comes up from the Mod Manager:

System.UnauthorizedAccessException: Access to the path 'mods/' is denied.
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.Directory.InternalCreateDirectory(String fullPath, String path, DirectorySecurity dirSecurity)
at System.IO.Directory.CreateDirectory(String path, DirectorySecurity directorySecurity)
at ModManager.Program.a(String A_0)
at ModManager.Program.RunModManager(String client)
at ModManager.Program.a(String[] A_0)

I have tried reinstalling the entire game client; and it still comes up as this. I didn't appear to have a mods folder in the game client folder; so i added one, and the problem remains the same. Also have tried running as Administrator; problem remains the same.

Any ideas?

Do you have an Administrator Account on that computer? The system has no access to some directory, so either you don't have the permissions or it does not exist.