XtraMile, Inc.

Issue:

When deploying your web application to IIS that uses SQL Express database, you get an error stating that “Failed to update database ‘APP_DATA\XXXX.MDF’ because the database is read-only”.

Here’s how you can fix it:

1. Make sure App_Data directory or any contained files does not have file system attribute Read-only set.
2. Give user ASPNET and NETWORK SERVICE Modify control over the App_Data directory.
3. Run IISRESET to restart IIS to refresh its permissions