Archive for category ASP.NET

Fixing SQL error 5170: Cannot create file ‘C:\[…]\APP_DATA\ASPNETDB_TMP.MDF’ because it already exists.in ASP.NET

The problem I recently had, for the first time, to create a brand-new ASP.NET web application that made use of the built-in Membership/Roles functionality, using the default of SQL Server Express, NOT a full installation of SQL Server. I had previously wrestled with issues when upgrading an older application using Membership/Roles to ASP.NET 4.0, and […]

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ASP.NET/SQL Server: Failed to generate a user instance of SQL Server; Login failed for user ‘NT AUTHORITY\NETWORK SERVICE’

While working on an ASP.NET 4.0 web application that uses the built-in Membership tools, I recently encountered the above two errors which prevented the site from working until sorted. I suspect the errors were triggered by the SP1 update to SQL Server 2008, as the application was working fine prior to my finally applying the […]

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