Fresh Install - Missing References

Team
I tried installing a new instance of NopCommerce 4.4 however when trying to build the application, almost all references including System dlls and package references are missing. This is straight out of the box code that was unzipped so no customizations at this point. I installed .Net 5.0 and am running this in VS2019. I'm not sure what I'm missing

You are using the source code version
Are you sure the unzip to a directory worked correctly
Maybe try the process again

If you downloaded the Source code version, the file should be named:
nopCommerce_4.40.4_Source.zip

Unblock the .zip file before extracting (Right-click > Properties > Unblock)

Thanks for the suggestions. I unblocked the zip file and that unfortunately didn't work. It turns out that I needed to get a more recent version of Visual Studio 2019. It has to be at least 16.8 or above. Maybe this should be mentioned in the pre-requisites for the installation. I found the answer in the comments section in the following link
https://vmsdurano.com/reasons-why-net-core-5-is-not-available-in-visual-studio-2019/

Yes you need to update VS to latest version
And also install sdk of asp.net 5.0
Then it will not raise any error