Design time error with System.Data.SqlClient

Question

We are using Visual Studio 2022 version 17.5.3 Our C# WINFORM projects use System.Data.SqlClient library to manipulate data but
All forms' design view have following error and not opened properly after update visual studio Unable to cast object of type 'System.Data.SqlClient.SqlCommand' to type 'Microsoft.Data.SqlClient.SqlCommand'. But project can be complied and worked without any issue though. Also, I attached screenshot of empty winform project. (C# winform .net 4.6.1) I added components SqlConnection, SqlCommand, SqlDataAdapter from SqlClient.Data.SqlClient to toolbox. Error message pops up when I add any of them to design view of form. But these errors are not occurred with Visual Studio 2019. Untitled-3.jpg

Answer 1

Hi @Gilbert Seong , 

Welcome to Microsoft Q&A! 

I could reproduce your issue on my side and found the same feedback from other community users:

VS IDE: Unable to cast object of type 'System.Data.SqlClient.SqlCommand' to type 'Microsoft.Data.SqlClient.SqlCommand'. - Developer Community (visualstudio.com) 

Windows Forms designer since VS 17.5: "Unable to cast object of type 'System.Data.SqlClient.SqlCommand' to type 'Microsoft.Data.SqlClient.SqlCommand'. - Developer Community (visualstudio.com) 

It seems be a known issue. You can also vote it and add your comment there to track the process.

If there are any updates, I will sync here. 

Sincerely,

Anna

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