Just ran into this. In short, stuck Windows Updates in progress caused the Sage installer to hang when it tried to install the .NET prerequisites.
I ran into the stuck message "please wait ... now installing prerequisites ". This was installing 2020.2 on Server 2016 running in a Hyper-V VM. The IT guy clicked on Start / settings button / Updates and saw Windows Updates being installed, in progress. Then while trying to click around looking for a way to pause them, he landed on this Retry message below. As soon as he did that, the Sage installer continued and immediately got pass the .NET prereqs !!

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Alnoor Cassim
Email:
alnoor@asifocus.comPh: 949-689-9887
Orange County, CA
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Original Message:
Sent: 01-26-2016 15:11
From: alan niergarth
Subject: I'm staring at ""Please wait while Sage 100 enables
We usually do the installation remotely then go on-site for the face to face stuff