FlexCelDyn.dll cannot add reference

Yesterday I activated licence for developer tools FlexCel.dll but since I downloaded and istalled app I can't add reference to my project and use that dll. What could be problem?
App is ASP.NET MVC .net 4.5.

Maybe ask in the correct forum section? This one is for FixInsight, not for FlexCel :)

Please use this forum: