I just tried to run ZK Lobby and it told me I didn't have .NET Framework 4. Most modern Windows computers will have the .NET 4 Client Profile installed, but not the full .NET Framework 4 (Client Profile is a stripped-down version of framework 4)
The problem is that if you google the .NET 4 Download page, you'll get a link to the Client Profile that
doesn't tell you it's the Client Profile, it just calls itself .NET 4. The full .NET 4 can be obtained from this link:
http://www.microsoft.com/en-us/download/confirmation.aspx?id=17718Unfortunately MS is pushing the stripped-down Client Profile very hard, while many library-developers still target the full .NET framework. iirc, Licho was using a JSON library that had this problem, hence the change to the full .NET framework away from the client profile.
Unfortunately, MS does
not make getting the full .NET framework pleasant - they seem to intend it as a server-only technology. So no auto-fetching, no nice built-in link in the installer failure.