I tried to start Platinum this morning and got a missing file error.  The only option I saw was to Rollback, which I did to the Allston update.  Sonar now works OK.  However, the CCC still thinks the Jamaica Plain is installed and does not give me an option to upgrade.  I restarted the PC and that did not work.  I deleted the Jamaica Plain update and restarted the CCC but that did not work. I forced CCC to check for updates but that did not work.  CCC still thinks the 21.9.0.40 is still installed.
 

Update.  I did an uninstall and reinstall of the CCC and that did not help.  Maybe something in the Registry?

Update 2.  Got the CCC to recognize an update was needed and did the Jamaica Plain update. 
However, I had to use "Revo Pro" Uninstaller program that allows removing registry and data files. 
Reinstalled the CCC and did the update to Jamaica Plain.  However, all the other modules have a Red "dot" and will need reinstallation to make CCC happy.
 

I have opened CWBKN-41028 for this problem. 
There should be an option to reinstall the current version without having to "jump through hoops" as I had to do.
CCC should also detect what is installed instead of just listing everything as not installed after the uninstall (and registry entry deletes) and reinstall.
 
 

Should this happen again before purging the registry with a registry cleaning tool try manually running the installer the Command Center reports is installed. If you do not delete the installers, they are located in the Download Path specified in the Path tab in the Command Center settings. Click the gear in the upper right of the Command Center UI to access the settings. If the installer has been deleted, download it from your account.

I had deleted all the download files.  Didn't make any difference.  CCC was still showing the Jamaica Plain as the currently installed version, even though the actual installed version was the Allston version.  The only thing that worked was the Revo Pro uninstall that can also (optional) delete registry files, the PC reboot and new install of CCC.   
I guess I could have searched the registry for the entry and deleted that.  But, that's now how things should work.  Instead of relying on a registry entry, the CCC program should look at the actual version installed.  Same way with all the other items installed, such as Melodyne, AD2, Rapture, etc.  They were all installed (and working) but CCC apparently does not check for actual installs and thus was listing them as not installed. 

fireberd
I had deleted all the download files. 

If this is the case next time, try downloading the installer the Command Center reports as running from your account and run it manually. This should sync up your installation with the Command Center. All the previous downloads are available here https://www.cakewalk.com/My-Account/Products
 
The Command Center should not fall out of sync and should report the version actually installed but I have seen similar issues in the past when rolling versions back and forth.
 

Thanks for the info on downloading direct.  I'll keep this in mind. 
But, again the CCC is supposed to be the vehicle to download anything, so it should allow reinstalling the current version and should know what is actually installed.