Maybe your system is not compatible. Did you check?
As Test Screen Name suggested - first check that you meet the system requirements (particularly your operating system)
If you do, try signing out of the desktop application and then back in again.
Just checked the specs and I need to upgrade my os. That should do it. Thanks guys.
I have this same issue. I meet requirements. Have MacOS High Sierra. Have the additional requirements on a new iMac. My up-to-date version is 2015.5.1 for Ps CC. Just updated it. Using Lr cc Classic. I uninstalled and reinstalled the creative cloud desktop. Still no 2018 update option.
davescm- I sent you an email too.