TNS oracle connection failed from MVC3 site using ASP.NET Membership provider

Question

We have an MVC3 site that uses the ASP.NET Membership Provider with Forms Authentication to let users onto the site. We have an Oracle database behind it.

It all works in house on development machines, test machines and deployment machines.

But at a client - they are getting the error "ORA-12154: TNS:could not resolve the connect identifier specified".

We thought this would be a simple case of a wrong config entry but all seems correct. They've also run a tnsping to the same TNS alias and it works. A connection via SQL*Plus also works. We've even got them to download a .NET connection string tester application and that connects ok using exactly the same connection string as the MVC3 site web.config has. It's only the website that comes back with this error. (note: all the tests were done from the same machine as the website is on)

Has anyone seen this before and provide some guidance on how to solve?

Thanks

Answer 1

The likely cause for this, from experience, is that the account under which the application is running is unable to read/access the TNSNAMES.ORA file, either due to file/folder permissions or network access permissions.