Viewstate Error in asp.net 4.0 web-application

Question

I have an error in an web application writen in asp.net 4.0 with c#. There is a viewstate or viewstate-MAC error with the following message:

[FormatException: The Input is not a valid Base-64-String....]
.
.
[ViewStateException: Invalid ViewState....]

I´ve tried everything I found on the web for this error. The error appears if the user clicks on an icon redirecting to the details patch of the selected item of an ListView.

• setting a machine key (allthough the app isn´t hosted on a webfarm or cluster)
• Validation of viewstate MAC failed error I have tried this without success
• and a lot of other things

I hope anyone can help me with this frustrating error. Thx in advance to all of u...

Answer 1

Since your application is not distributed, try adding this to your web.config :

<pages enableViewStateMac="false">