ValidateRequest="false" directive . still fails

wbr tag

html5 video tag

html5 var tag

html5 ul , ol ,li tags

html5 track tag

This happens in asp.net 4.0
as a migration step add..
<system.web>
<compilation debug="true" targetFramework="4.0" />
<httpRuntime requestValidationMode="2.0" />
</system.web>