Invalid postback or callback argument. Event validation is enabled using
what made this move interesting is that the page is a aspx page that was converted from a asp page some time ago and that it was still configured as a dot net 1.1 app in iis. When I moved it, i saw the aspx ending and set it us as a dot net 2.0 app. Changing it back fixed my issus.
I did find this link to a related issue and would have tried those steps if my trick did not work.