The long awaited new version of XPUIPC for X-Plane 12 is out and available on www.xpuipc.com.
Please note, this is a completely new version and has its own codebase, it also has a new XPWideClient.
For X-Plane 11 and older, please keep using the previous version of XPUIPC.
http://xpuipc.com/