The JSON request was too large to be deserialized.

Corrección en el Web.config:

<system.web.extensions>
    <scripting>
        <webServices>
            <jsonSerialization maxJsonLength="2147483644"/>
        </webServices>
    </scripting>
</system.web.extensions>

<appSettings>

  <add key="aspnet:MaxJsonDeserializerMembers" value="150000" />
</appSettings>