Issue Connecting With An Azure SQL Database from .NET WinForms Application

Tom 1

I'm having an issue connecting to an Azure SQL database from a WinForms application after it has been packaged using InstallShield. The database exists on a virtual network and I'm using a virtual network gateway point-to-site connection. The database is using Entra authentication and the application is using a service principal to connect. I have updated the hosts file to use the correct connection.

The code works when running the application using Visual Studio. I've checked the DLLs installed when the application has been packaged and they are the same. Looking at the database logs, it seems that the service principal is not accessing the database. No errors are being raised but the database queries are not receiving results. This is more difficult to test because the code is working in VS but not after packaging with InstallShield.

How can I fix this?

Oury Ba-MSFT 17,791 Reputation points Microsoft Employee

2024-05-22T21:55:13.0933333+00:00

@Tom Thank you for reaching out.

Sorry about the issue you are facing. Could you please check if you have assigned the necessary permissions to the service principal to access the Azure SQL Database. In the Azure portal, could you also verify that you have configured the firewall rules for your Azure SQL Database to allow traffic from the IP address of your WinForms application.

https://learn.microsoft.com/en-us/azure/azure-sql/database/azure-sql-dotnet-quickstart?view=azuresql&tabs=visual-studio%2Cpasswordless%2Cservice-connector%2Cportal

Regards,

Oury
Tom 1 Reputation point

2024-05-23T17:32:23.2866667+00:00
Hello @Oury Ba-MSFT

The service principal is working because it is the same one I'm using through Visual Studio. As far as I can see the database connection is fine as I can connect to it from other applications on the machine.I did get a stack trace of an error that is raised when the following code is run.

Using conn As SqlConnection = New SqlConnection(_ConnectionString)

I am using the Microsoft.Data.SqlClient DLL.

The error raised is

Error: Could not load file or assembly 'System.Memory, Version=4.0.1.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) Stack Trace: at Microsoft.Data.LocalDBAPI.GetLocalDbInstanceNameFromServerName(String serverName) at Microsoft.Data.SqlClient.SqlConnectionString..ctor(String connectionString) at Microsoft.Data.SqlClient.SqlConnectionFactory.CreateConnectionOptions(String connectionString, DbConnectionOptions previous) at Microsoft.Data.ProviderBase.DbConnectionFactory.GetConnectionPoolGroup(DbConnectionPoolKey key, DbConnectionPoolGroupOptions poolOptions, DbConnectionOptions& userConnectionOptions) at Microsoft.Data.SqlClient.SqlConnection.ConnectionString_Set(DbConnectionPoolKey key) at Microsoft.Data.SqlClient.SqlConnection.set_ConnectionString(String value) at Microsoft.Data.SqlClient.SqlConnection..ctor(String connectionString, SqlCredential credential) at Microsoft.Data.SqlClient.SqlConnection..ctor(String connectionString)

How can I fix this issue?
Oury Ba-MSFT 17,791 Reputation points Microsoft Employee

2024-05-29T20:14:39.26+00:00

@Tom Sorry for the late reply on the above. I missed to see the last comment.

You mentioned above that the service principal is not accessing the database.

Check if the service principal has the necessary permissions to access the Azure SQL Database. Microsoft Entra service principals with Azure SQL

Could you please check this issue https://stackoverflow.com/questions/93879/hresult-0x80131040-the-located-assemblys-manifest-definition-does-not-match-t

"The HRESULT: 0x80131040 exception is commonly associated with missing dependencies or issues with loading assemblies in .NET applications. It often occurs when the runtime is unable to locate a required DLL or when there are conflicts between different versions of assemblies.

Please check if this solution below from the above stack overflow issue.

We encountered a situation where multiple .NET frameworks were being used, each relying on different NuGet packages. To address the issue, we attempted to install the same version of the packages across all projects. However, despite our efforts, the error persisted. Surprisingly, when we created a new project within the solution and implemented a method(...), it worked flawlessly.

If the issue persists. I would suggest raising a support ticket.

Regards,

Oury
Oury Ba-MSFT 17,791 Reputation points Microsoft Employee

2024-06-03T18:11:31.2133333+00:00

@Tom Tom Were you able to check the above comment.?

Please share current status of the issue.

Regards,

Oury

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Issue Connecting With An Azure SQL Database from .NET WinForms Application