Hi there!

The problem like this may occur if you use integrated auth for your database access from ASP.NET application. MS built-in web server runs under interactive (logged in) user account. Therefore, if DB connection string specifies integrated auth, you will access DB as current interactive user. When you use UltiDev Cassini, which runs under “LOCAL SYSTEM”, the application talks to the DB as under LOCAL SYSTEM login.

To resolve this you may do one of the few things:
- Create a new user-login mapping in the SQL Server for “LOCAL SYSTEM” (a.k.a. “NT AUTHORITY\SYSTEM”);
- Or create a low-privilege windows user especially for DB access and either run Cassini under such account, or create a Serviced Component (COM+ object) running under the account;
- Or run UltiDev Cassini under your current user account (not recommended for security reasons);
- Use mixed auth model with SQL Server and add username and password to SQL connection string in web.config. This option is not the best from security stand point, but can be used behind firewalls in small organizations.

For more information refer to MSDN’s topics that talk about different ways to connect to the DB from an ASP.NET applications/.

Regards,
UltiDev Team.