Hi @yan huang ,
Which version of Visual Studio are you using?
Please close all running instances of Visual Studio and update your VS to the latest version.
Then, create a new project and add a new table.sql file to check if the Table Designer is appeared.
Meanwhile, you can also repair your VS through Visual Studio Installer > More > Repair.
If it doesn’t work, please share us some screenshots about the complete error message so that we can investigate it further.
Sincerely,
Anna
*
If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.