Can’t update OS from App Store
I’ve recently wiped everything on my mid-2010 iMac and was able to update to snow leopard. I’ve installed all available updates but for some reason can’t download newer OS versions from the App Store. I started with El Capitan but every time I try the download time is in the double digits and never finishes. I’ve tried earlier versions and get the same thing. I was running High Sierra before I did all this and would like to get back to that. My internet is fine as everything else downloaded fine but it appears that something is wrong with my version of the App Store. What would be the cause of this and how do I fix this?
iMac 21.5", OS X 10.11