I tried tonight to update our site to use StateServer for session state management instead of InProc. As soon as I made the change I got this error whenever I visit the front of my site (but weirdly not the admin page):
Unable to serialize the session state. In 'StateServer' and 'SQLServer' mode, ASP.NET will serialize the session state objects, and as a result non-serializable objects or MarshalByRef objects are not permitted. The same restriction applies if similar serialization is done by the custom session state store in 'Custom' mode.
Why cant I switch to using the StateServer? I have it enabled in services and set to Automatic. Its started as well.
It appears you have some objects (classes) which you are storing in the Session State. You will need to explicitly add the [Serializable()] attribute to the class declaration.
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