Error running nopcommerce 4.605 in iis

As a follow up, I downloaded nopcommerce 4.604 and it would not start either. ( I shut down the other website before trying to start).

I added the website to the older 4.0 nopcommerce site which is running and it runs fine.

Can anyone verify that they are running 4.6* in IIS without issue?  
Does nopcommerce have any utility to test that all prereqs are installed properly?

Thanks,
Rick

_rick wrote:
Not sure what you mean here - is this a different server or ?

_rick wrote:
Yes it works fine

_rick wrote:No - normally you go through all the steps and fault finding which has already been mentioned

As previously mentioned, I have an older version of nopcommerce (4.0) running in iis on the same server.  It is my understanding that I can run multiple versions of nop side by side.  They each use their own application pool and are obviously installed in their own folders.  I tried turning off the older version but the new one still is not running.  Is this a problem?

Ok I guess you mean both have the same domain names
Not a problem. Separate websites with separate application pools on the same server is fine.
Stop one and start the other.

No, the nop4.0 is running its own websites, totally different domains.
I'm setting up a new website for a new domain and I wanted to use the latest version of nop.
Since getting nopcommerce to run isn't going well, I've since added the new domain to the old nop4.0 web and the new domain runs fine on it, on this same server.  I now mark out the bindings for this new domain and restart as I try to start the new nop, I realize the domain can't be bound in two sites.

I have tried (several times) turning off the nop4.0 website, restarting IIS, then starting the 4.605 website, no changes, error code 500.

I just downloaded the x86 version of nopcommerce 4.605, just to see if would load since I had been trying the x64 version.  Nothing changed, error code 500.
In looking at control panel, I have:
Microsoft ASP.Net Core 7.0.5 - Shared Framework (x64 and x86).  Also 7.0.14  
Microsoft .Net Runtime 7.0.5 (x64 and x86) Also 7.0.14
Microsoft .Net 7.0.5 Windows Server Hosting
Also: Microsoft .Net Core 2.1.4 Windows Server Hosting and .Net Core Runtime 2.1.4
Microsoft .Net Framework 4.5.1
Anything missing?

when running the command I get
>dotnet --info

Host:
  Version:      7.0.4
  Architecture: x64

.NET runtimes installed:
  Microsoft.AspNetCore.App 7.0.4 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 7.0.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]

I finally have nopcommerce 4.605 running and nop 4.0 running.
I'll spare you all the variations of this process I went through that didn't work and just share the one that did work.
I uninstalled all versions of:
Microsoft .Net - Windows Server Hosting, Microsoft .Net Core Runtime, Microsoft ASP.Net Core,
Microsoft Net Runtime then rebooted the server.
I then installed version 7.01 of all of the above, both x86 and x64 using the hosting msi package.  I edited the Environment Path to move the Program folder to come before the x86 folder to get the Host to load the x64 version.  (cmd:> dotnet --info) This allowed nop 4.605 to run as x64.  I then disabled allow x86 in the application pool settings.
I then installed version 2.1.30 of all of the above, both x86 and x64 using the hosting package.  This allowed nop 4.0 to run as well.
From my experience, the order was important, doing things in different order and using different versions may also work, they were not working for me.
While I would expect version 7.01 or higher to be backward compatible, they were not, both 7.01 and 2.1.3.0 needed to be installed.  
This issue may only appear when trying to run an older nopcommerce alongside a newer one, but there were very few clues given to get to a solution.  Hopefully it will be helpful to someone encountering the same issue.
Thanks to Yidna for the help and suggestions along the way.
Rick