The issue is because SME cannot be sure which Exchange server is installed on your system.
You can do following to troubleshooting:
1) enable SME debug logging.
2) restart SME MMC Snapin.
3) check application event log, it will have an entry stating the OS and Exchange version SME detected.
4) check SME debug log.
Note above should be done from the owner node of the Exchange virtual server.
Thanks,
-Qing