Invalid where condition. An entity member is invoking an invalid property or method

I had recently been requested to perform a query in Dynamics CRM database using Linq without EntityGeneratedCode aid, that's when I came up with this error: "Invalid 'where' condition. An entity member is invoking an invalid property or method.".

I thougth it was some syntax error I had gotten, however it was not. Take a look at the code at this moment.

  Guid id = new Guid("2C2B13B2-E881-E311-93FA-00155D1E6428");
   var query = from c in orgContext.CreateQuery("account")
                     where ((EntityReference)c.Attributes["accountid"]).Id == id
                     select c;

With some help I found out that it's a frequent error when using linq. It's pretty easy to solve that, I just had to put off the "Attributes" string from the query. So it's like that right now.

 Guid id = new Guid("2C2B13B2-E881-E311-93FA-00155D1E6428");
  var query = from c in orgContext.CreateQuery("account")
                    where ((EntityReference)c["accountid"]).Id == id
                    select c;

I still don't know why it must be this way, but anyway, that's the way I found to fix that.