Because View State is stored in a hidden field on a Web page, it is vulnerable to tampering when data is being transferred between the client and the server. To help make View State more secure, ASP.NET validates View State to verify that it came from the correct page.
If ASP.NET cannot validate View State, ASP.NET returns a message to the client browser that states that "viewstate is invalid for this page and might be corrupted." However, the message does not describe why View State is not valid.
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