I just woke up this evening and tried to access my web application and this was the error i got:

Server Application Unavailable

The web application you are attempting to access on this web server is currently unavailable. Please hit the "Refresh" button in your web browser to retry your request.

Administrator Note: An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur.

I have tried removing all my files on the server and putting them back but i still get the same error. I really don't know what to do. Nairaland Programmers please come to my rescue. the website is www.ephodng.com Maybe you guys can check it see the error for yourselves. The web application works fine on my local system. I also checked my application log on my server but didn't find any useful information. Please i really need help on this one!

The 2nd paragraph of that error msg states that you should check your server logs.  Have you done that?  Either way, you can always contact your web host.  Other possible reasons: You don't have an index file and probably need to type the full file path to see the page, Site is down due to lack of payment, web host performing maintenance and domain name has expired, to mention but a few.

The problem has been rectified, it was a problem with the server's ASP.NET coding script! Thanks Nairalanders!