I am also getting a request validation error when using WIF. I get correctly sent to the STS, but on the way back, I get this validation error.
I followed all the i
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also in mvc3 there is an AllowHtml attribute
[AllowHtml] public string Property{ get; set; }
here are some useful links
ASP.NET MVC – pages validateRequest=false doesn’t work?
Why is ValidateInput(False) not working?