Nice one JazzHot !!
I too did the same as you & disabled Spotlight with Spotless sometime ago as I found it's incessant disk churning annoying, and so I read your tip & just switched on Spotlight again using Spotless & the AppStore worked... it even let me login & click the UPDATE button to see what was new, whereas before it wouldn't even show me a login screen & would just hang & show the dreaded beachball !
At first I thought this was a fluke, so I rebooted (with Spotlight still re-enabled) & tried the AppStore again, and it still worked & I was able to download 2 Free Apps too !!
And for the doubters, no I didn't have iTunes running at the same time, and no I hadn't run iTunes before & logged into the iTunes Store either before trying this, and also I have OCSP & CRL both turned OFF in my KeyChain Access - Certificates section, as per previous comments.
Why on earth does AppStore need Spotlight to be enabled ? Does the AppStore need to see the scanned contents of your machine (thanks to Spotlight scanning your machine) before it lets you install something ? Surely the AppStore doesn't need to know what's on your machine to install something & isn't that an invasion of privacy ? Can someone please answer this as to why AppStore needs Spotlight switched on ???!!!
Either way a big thanks to you JazzHot for finding this fix & helping me out & hopefully others too... buy yourself a beer 😁