Sitecore Identity Server HTTP Error 502.5 - Process Failure

I recently installed Sitecore 10, using SIA, on a brand new machine. Note that I didn't install anything dotnet (like, Visual Studio) apart from Sql Server.  Since its a new machine, as ever, I installed the pre-requisites through SIA and could see Windows host bundler 2.1.15 get installed. 

After the site install, I verified the same in this location -

Then, as part of sanity check, I tried to access the identity server url and this is what I saw:

I then opened the event viewer to check for any clues and this is what I saw:

Then, switched over to command prompt to understand more about the error so, executed dotnet .\Sitecore.IdentityServer.Host.dll in the root path of the identity server and I received this message:

I frankly didn't expect this since I thought the pre-requisites installer covers for any needed environment setup. Anyway, I decided to install the Windows hosting bundler 2.1.16 version.

Post-install, I cross-verified the presence of 2.1.16 folder under C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App. 

I just accessed the identity server and could reach the identity server now -

So, the pre-requisite installer for Sitecore 10 SIA doesn't install the correct Windows bundle  version, which is Windows hosting bundle 2.1.16. I hit this error since I had a new machine and didn't install any bundlers apart from the one installed by SIA (and, it installed windows bundle 2.1.15 instead). 

Initially, I didn't suspect the SIA installer and did a factory reset thinking there is something wrong with my machine but only when I started suspecting the pre-requisite installer, I decided to look at the event viewer and I got the answer.

So, next time, start suspecting things instead of thinking everything is perfect!