IIS seems to not being able to connect using Entity framework provider-CodePudding

I've being trying in vain to solve a problem on a newly created windows server with IIS hosting an ASP.NET application that was copied from another environment. The issue is that I cannot manage to connect to the database when the application tries to open a connection via entity framework.

If this is off topic for SO let me know so I can move to another channel, I thought it belonged here as seems specific to EF.

In detail, I have the following connection strings:

<connectionStrings>
    <add name="ApplicationServices" connectionString="Data Source=LOCALCOMPUTER\SQLEXPRESS;Initial Catalog=xxx;Persist Security Info=True;User ID=yyy;Password=zzz" providerName="System.Data.SqlClient"/>
    <add name="MembershipConnection" connectionString="metadata=res://*/App_Code.Membership.Membership.csdl|res://*/App_Code.Membership.Membership.ssdl|res://*/App_Code.Membership.Membership.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=LOCALCOMPUTER\SQLEXPRESS;Initial Catalog=xxx;Persist Security Info=True;User ID=yyy;Password=zzz;MultipleActiveResultSets=True;Application Name=EntityFramework&quot;" providerName="System.Data.EntityClient"/>
    ...

xxx, yyy, zzz of course have the proper values. LOCALCOMPUTER is the FDQN of the local computer, which is not on a domain

The first connection string is for the Microsoft login library, while the second uses entity framework from our code.

When I browse to the site, I can successfully access the login form, and if I try to insert a wrong password i get a message saying so, meaning the application managed to check the database using the first connection string, but when i insert a correct one, i land on an exception as soon as the code tries to create a context.

The underlying provider failed on Open.: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - The wait operation timed out.)

In the event viewer it tells me that the user has been authenticated via Authentication Type: Forms , which I assume it means the auth system (the one using ApplicationServices connection string) is working, the stack trace confirms that the error occours when I try to use EF in code, meaning the DB has been used succesfully to check user credentials

note that:

The web app works in other environments
I can connect to the sql server using the credentials via SSMS
I've assigned a local windows account to the app pool that can also access the database, and tried changing to Integrated Security=SSPI
Both .Net 3.5 and .Net 4.8 are installed

The database is on the local machine and has been restored from a dump of the other one, its users have been mapped, and to rule out issues i gave it ample authorisations with dbowner datawriter and datareader

I've been trying to fix this since a couple days checking similar issues on SO with no avail and I don't really know how to proceed, is there something I can do to troubleshoot the issue?

CodePudding user response：

Apologies, I've found out the answer, and it's specific to the code base. Apparently the connection string was being ignored (despite being perfectly usable) in favour of data saved in a table.

Had to contact the previous developer to find out, guess it's a good example of how important is to document your code

I'll close the thread, thanks for all who tried to help