Nunut tests fails when many projects in solution must be tested

Hello!

We have a solution with ~20 projects + ~20 unit tests projects (we used Nunit). In resharper or via nunit tests launcher(on local computer) - all runs good, no errors occurs. But in TC we get this error:

System.Data.Entity.Core.ProviderIncompatibleException  : An error occurred while getting provider information from the  database. This can be caused by Entity Framework using an incorrect  connection string. Check the inner exceptions for details and ensure  that the connection string is correct.   ----> System.Data.Entity.Core.ProviderIncompatibleException : The provider did not return a ProviderManifestToken string.   ----> System.Data.SqlClient.SqlException : 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: 26 - Error  Locating Server/Instance Specified)

The impression that TC reads connection strings from one project, and caches it for all remaining projects.

If leave only one project - tests runs good (connection strings in app.config of different projects are different). Checkbox "Run a process per assembly" in build settings does not help. How to fix this? Or, for a start, how to view command line of nunit and dotcover launchers, which executes unit tests?