If at first you don't succeed ... I'll pass along my experience (and it's been needed by a few others here also) ...
I got a mess during downloading/installing through being my typical impatient self ... rather than waiting for each program of the CC updates available to do it's thing to completion BEFORE starting the next, I did several. BAD ... VERY BAD! Sigh.As it seems, not recommended ... ahem.
When I then ran the CC Cleaner, the instructions said use your system tools to uninstall & cleaner to scour, then re-install. Got me back to exactly the same non-working place. So ... with all the offending programs "up" ... I used the CC Cleaner to remove everything INCLUDING 'uninstalling' the programs, THEN downloaded fresh ones one - by - one then installed each ... and was back working.
So ... with your current "ish" of Sg installed, I would suggest running the CC Cleaner and removing minimally your Sg and the Creative Cloud desktop app, then downloading the CC Desktop app anew, installing it, THEN going for a new download/install of SpeedGrade.
Your mileage may vary, of course ... but this finally solved this type of thing for a couple other poster's here recently.
Neil