NOTE: Requested to move the question from StackOverflow to dba
Don't know if this is really a SQL Server problem or not.
Client moved to TLS 1.2, it broke an app that connects to SQL Server 2017 and it got dumped on my lap.
Being a Linux person all I can say is when they went back to TLS 1.1 it worked and here is the only error message I can glean in all this mess:
dbnetlib connectionopen secdoclienthandshake ssl security error
In SS Studio, when I click on the DB I get this error message:
Error connecting to 'hostname'.
Login failed for user 'CORP\myaccount'. (.Net SqlClient Data Provider)
Server Name: hostname
Error Number: 18456
Severity: 14
State: 1
Line Number: 65536Program Location:
at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, String accessToken, Boolean applyTransientFaultHandling, SqlAuthenticationProviderManager sqlAuthProviderManager)
at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup, DbConnectionOptions userOptions)
at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
1 retry, DbConnectionOptions userOptions)
at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource
at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource1 retry, DbConnectionOptions userOptions)
1 retry)
at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource
at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
at System.Data.SqlClient.SqlConnection.Open()
at Microsoft.SqlServer.Management.SqlStudio.Explorer.ObjectExplorerService.ValidateConnection(UIConnectionInfo ci, IServerType server)
at Microsoft.SqlServer.Management.SqlStudio.Explorer.ObjectExplorerService.ConnectToServer(UIConnectionInfo connectionInfo, IDbConnection liveConnection, Boolean validateConnection)
TLS 1.2 was turned/put on the server that hosts SS.