The same application configured in some other server. It's working fine without any error. Anything blocking https:// in that server....??
A 404 means the page was not found. I'm not sure what you mean by blocking https or how to force such a condition.
Keep in mind, your first URL is "avmsvr.avm.avmnet.intranet/Projects120/Login.aspx". The URL in the browser is avmsvr.avm.avmnet.intranet/Projects120/Apps/WebForm1.
I assume, as the error clearly states, WebForm1 does not exist in the Apps virtual directory. Or maybe it is the other way around and WebForm1 does not exist in the Projects120 folder.
Authentication : Windows Authentication enabled in IIS
Why is there a login.aspx page if Windows Authentication is enabled in IIS? That makes little sense.