Viewstate Error in asp.net 4.0 web-application

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开发者_StackOverflow社区 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.

Tried without success:

• 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...

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

<pages enableViewStateMac="false">