Event validation is enabled causing invalid postback or callback argument
Versions:
4.0,
FAQ number:
168,
Old FAQ number: 8862
This error is caused by running ASP.NET 2.0 with an incompatible web.config setting. In order to resolve this you need to set "enableEventValidation" to "false".
Open your web.config file and replace the <Pages> element to match the following:
<pages validateRequest="false" enableEventValidation="false">