Our DNN 07.02.01 website is running under webfarm, we are using two server web1 and web2 maintaining machine key in web.config file. Due to maximum n number of continues application pool recycle in DNN Event viewer we turned of the FCN mode. Now we are performing scheduled restarts for both server.

Problem is now we are getting View State Mac error frequently. Below error not coming for particular portal and page every time it occurs in different portals and different page. We are not able to replace this issue. Due to Security issue we can’t make enableViewStateMac="false" in web.config file.

Any one help me what is the exact root cause for this issue after maintaining Machine Key in web.config file. And also let me know how to replicate this issue manually.

InnerException:Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.

InnerException:The state information is invalid for this page and might be corrupted.

Both Server web1 and web2 System Configuration

Windows Edition – Windows Server 2012 R2 Standard

Thanks in advance

Gopinath