UserManager and organizational accounts - cannot connect to the database ( mvc 5) - asp.net-mvc

Question

Got the following problem:
I've created simple mvc 5 project with individual user accounts authentication.
Everything works i can add users,roles,everything is stored in the database - all seems to be fine. Now i want to change authetication to organisational:
<system.webServer>
<modules>
<add name="WSFederationAuthenticationModule" type="System.IdentityModel.Services.WSFederationAuthenticationModule, System.IdentityModel.Services, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="managedHandler" />
<add name="SessionAuthenticationModule" type="System.IdentityModel.Services.SessionAuthenticationModule, System.IdentityModel.Services, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="managedHandler" />
</modules>
</system.webServer>
<system.identityModel>
<identityConfiguration>
<audienceUris>
<add value="myUrl" />
</audienceUris>
<securityTokenHandlers>
<remove type="System.IdentityModel.Tokens.SamlSecurityTokenHandler, System.IdentityModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<add type="System.IdentityModel.Tokens.SamlSecurityTokenHandler, System.IdentityModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
<samlSecurityTokenRequirement>
<nameClaimType value="myClaim"/>
</samlSecurityTokenRequirement>
</add>
</securityTokenHandlers>
<certificateValidation certificateValidationMode="None" />
<issuerNameRegistry type="System.IdentityModel.Tokens.ValidatingIssuerNameRegistry, System.IdentityModel.Tokens.ValidatingIssuerNameRegistry">
<authority name="mySts">
<keys>
<add thumbprint="myThumb" />
</keys>
<validIssuers>
<add name="mySts" />
</validIssuers>
</authority>
</issuerNameRegistry>
</identityConfiguration>
</system.identityModel>
<system.identityModel.services>
<federationConfiguration>
<cookieHandler requireSsl="true" />
<wsFederation passiveRedirectEnabled="true" issuer="mySTs" realm="myUrl" requireHttps="true" />
</federationConfiguration>
</system.identityModel.services>
It works - i can authenticate,but when i want to add new user (based on User.Identity.Name to my existing database:
UserManager.CreateAsync(user);
I get weird error:
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: SQL Network Interfaces, error: 50 - Local Database Runtime error occurred. Cannot create an automatic instance. See the Windows Application event log for error details.)
although i didn't change anything in connection,dbcontext and so on.
What could be a reason of such behavior?

Answer 1

Something seems to be missed in your web.config file. Try to add connectionStrings to your web.config by editing the code below according to your database and connection properties:
web.config:
<configuration>
<add name="DefaultConnection" providerName="System.Data.SqlClient" connectionString="Data Source=(localdb)\v11.0;
Initial Catalog=aspnet-YourDatabaseName; Integrated Security=SSPI; AttachDBFilename=|DataDirectory|\aspnet-YourDatabaseName.mdf" />