ISSUE:

404 or 500 errors or Under Construction error

RESOLUTION:

There may be different causes for this. Check the following:

 - The ASP.Net version.

    - DNN 5.x should have ASP.Net 2.0/3.51 set

    - DNN 6.x/7.x should have ASP.Net 4.0 set

    - In your Plesk Control Panel you can set the ASP.Net version under the Hosting Settings  or Web Hosting Settings option.

- File and Folder Permissions. DNN requires that the IWPD or IWPG user has modify rights on the site. On Plesk 10.x and above you can set this at the root level and push permissions down using the Plesk File Manager. The KB article below explains how to mange your file permissions in Plesk 11 and 12.

  http://knowledge.3essentials.com/web-hosting/article/2221/HOW-To-Edit-Folder-and-File-Permissions-in-Plesk-11-and-12.html

- If you receive a error such as HTTP://YOURDOMAIN.COM/install/UnderConstruction.htm it may mean that your application pool has lost connection to the MS SQL database.  DNN doesn't retry these connections once they fail. To test to see if this is the issue open a browser URL to your domain using this URL: HTTP://YOURDOMAIN.COM//install/install.aspx?mode=upgrade .  If you receive a cannot connect to db error then this is the issue. To resolve, login to Plesk and restart your websites application pool.  If this doesn't fix the issue then

  - Check your connection string to make sure it is accurate.

  - If the connection string is accurate then it is possible the SQL login is not synced. In MSSQL databases there is an id in the database, but to connect remotely, an identical SQL Login is created in MSSQL server. These two uids must be synced with each other to allow the login. These can get out of sync during database restores. You can sync the SQL login by simply resetting the password using the Plesk Control Panel. In the control panel where you created your database you will see a user tab. Click the uid and fill in the password to reset it.

  - If neither of the options above correct the issue, try restarting your MSSQL server. If you are on Shared hosting or Managed server hosting, contact support contact the support team.