Failed to load viewstate. Happening only occasionally. Tough to recreate

Question

Details of Error are given below. This error happens only occasionally / rarely / sometimes and there aren\'t any steps to reproduce it.

How can I know which Control

Answer 1

I experienced the exact same problem. I had 2 listview in a Master page, associated with 2 updatedpanels.

Disabling the EnableViewState on the Listviews solved it for me!