>>>>Hi,
>>>>
>>>>I installed an ASP.NET application on a new VM. I did the same steps as 100s of the times before. Usually I test the application by browsing test.htm from the IIS Manager. Then I go to test other pages.
>>>>But in this case, when I try to browse test.htm (which has just one line) the browser reports error:
>>>>

>>>>Service Unavailable
>>>>HTTP Error 503. The service is unavailable
>>>>

>>>>
>>>>Where do you suggest I look at the IIS Manager or the server?
>>>>
>>>>TIA
>>>
>>>Have you tried accessing the web server from a workstation within the same network? Browsing the Web on the server itself is often a hit-or-miss affair (due to restrictions if you're logged in with administrative username -- *especially* Administrator ).
>>>
>>>And of course, there's the next stupid question -- did you make sure that the web site was indeed started?
>>>
>>>Another stupid question -- was this website set up with HTTP or HTTPS? If the latter, did you make sure that the SSL/TLS certificate was properly registered? If the former, double-check on the address bar of the Web browser that you're trying to access with http rather than https (some Web browsers will default to https)
>>>
>>>YASQ (Yet Another Stupid Question) -- have you tried navigating in File Explorer and try duoble-clicking on the test.htm? Just want to verify that it does open with a Web browser. If it opens in some other application, you may want to double-check that the file is indeed named "test.htm" rather than something like "test.htm.txt" (i.e. make sure that you're not running afoul of default configuration of Windows that hides the file extension).
>>
>>First, all your questions are valid and not stupid at all. I actually found a very long thread on Stackoverflow regarding this issue.
>>
>>Here is what I found so far. The site started. But the Application Pool stops as soon as I try to browse to any file. Then, after starting the pool and doing the same thing several times, I went to the Event Viewer. And I found that the reason is - possible - insufficient permissions to the folder (within IIS) where the application pool reside.
>>This is an old customer but they created a new VM. And they are very "protective" or "restrictive". I have been dealing with them for a few days. It is possible that they didn't give the IIS sufficient permissions.
>>
>>And, to answer another of your questions, if I simply open the test1.html from the browser, it works. Only it does not work when the file works in the site with this particular Application pool.
>>
>>Thank you.
>
>Another stupid question -- was the server (the one that's hosting the web server) rebooted after installing the Web Server role? Sometimes the server installation/configuration isn't complete until you've performed reboot (usually when you add/remove roles).
>
>As for user rights -- for older server (iirc 2003 and earlier) you assign access rights to user IUSR___ (where ___ his host name -- i.e. server name), while on newer server you asssign rights to group IUSERS (the group from which users are selected to be identity used for web server process).

The server was not rebooted. I have done tons of installation and never needed the server to be rebooted.
This is a new Server 2019.
Thanks.