D42AutoDisc client common error messages and resolutions are discussed below.
Also, the executable should be run as an administrator.
Exception Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

If you see following message:
Exception = Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))
Please make sure the service is running under a domain account and not local system account.
Exception The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)
In addition to above, please check this stackoverflow resource: http://stackoverflow.com/questions/11330874/get-wmiobject-the-rpc-server-is-unavailable-exception-from-hresult-0x800706?rq=1
Cannot post device detail to D42. Check URL/Credentials or License.
For message: Cannot post device detail to D42. Check URL/Credentials or License.
Please check you can connect to device42 instance from the browser. Otherwise, see if your license count has exceeded the number of licensed devices.