Sys.WebForms.PageRequestManagerServerErrorException: An entity object cannot be referenced by multiple instances of IEntityChangeTracker

[Nikola]

Heely Guys

Story: I have a strange error when I try to save something I got this error message ( An entity object cannot be referenced by multiple instances of IEntityChangeTracker.)
I really don’t know what that is and why is it appear, it appears only when I try to save something my insert and update is working, only when I try to save something in db from my grid

if (this.annualVacationList != null)
      {
          List<AnnualVacation> vacationToSave = this.annualVacationList;
          IEnumerable<AnnualVacation> existing = paramUser.AnnualVacations;
          foreach (AnnualVacation toSave in vacationToSave)
          {
              AnnualVacation existingItem = existing.Where(x => x.AnnualVacationId == toSave.AnnualVacationId).SingleOrDefault();
              if (existingItem == null)
              {
                  ctx.AddToAnnualVacations(toSave);
              }
              else
              {
                  existingItem.FromDate = toSave.FromDate;
                  existingItem.ToDate = toSave.ToDate;
                  existingItem.WorkingTime = toSave.WorkingTime;
                  existingItem.VacationDays = toSave.VacationDays;
              }
          }
      }
      ctx.SaveChanges();
  }

After debugging I have seen that the code brake down in the Project.Name.Designer.cs ..... O.o

public void AddToAnnualVacations(AnnualVacation annualVacation)
   {
       base.AddObject("AnnualVacations", annualVacation);
   }

[Maria Ilieva]

Hello Nikola,

The presented error is mostly a generic issue and not directly related to the RadControls. I would suggest you to review the online resources below which elaborates on this error:

http://social.msdn.microsoft.com/Forums/en-SG/adodotnetentityframework/thread/501d7b99-0cb9-44b6-b2cd-16275a151b31
http://stackoverflow.com/questions/620084/how-to-get-rid-off-an-entity-object-cannot-be-referenced-by-multiple-instances
http://forums.asp.net/t/1587926.aspx/1

Greetings,
Maria Ilieva
the Telerik team