Hi,
Based on my understanding, you configure the SqlDataSource control to connect Database. But the connection is lost when you reopen this project in Visual Studio, right?
Where do you save the connection string, inside of DataSource control or web.config file? You can try to save connection string to web.config file by selecting "Yes, save this connection as: " option while configuring it.
Do you do some special work on that page or could you please post a simple test code that be used to repro the issue? It will help us move more quickly toward a solution.
I look forward to receiving your test results.
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