title: operation cannot be completed because the DbContext has been disposed."
body: <p>While running the project am getting this error "The operation cannot be completed because the DbContext has been disposed".While checking the net I have seen many answers for this but I think I have that all in my code.Please verify my code and let me know what's wrong in it ,Please help me...
  This the code written in the controller and in the Elmah am getting the error.</p>
  
  <pre><code> public ActionResult Create(Permissions permissions)
      {
          try
          {
              using (var db = new AdminDb())
              {
                  //delete existing permissions of the selected role..
                  IList&lt;int&gt; ModuleMenu = (from d in db.MenuConfig.AsNoTracking()
                                           where d.ModuleId == permissions.ModuleId
                                           select d.MenuConfigId).ToList();
  
                  var RoleMenu = (from c in db.RoleMenuMapping where ModuleMenu.Contains((int)c.MenuId) &amp;&amp; c.RoleId == permissions.RoleId select c).ToList();
  
                  foreach (var rm in RoleMenu)
                  {
                      db.RoleMenuMapping.Remove(rm);
                      db.SaveChanges(); // Added for avoiding The object is in a detached state Error
                  }
  
                  // add new permissions to db
                  if (permissions.RoleMenu != null)
                  {
                      foreach (var rm in permissions.RoleMenu)
                      {
                          RoleMenuMapping RoleMapping = new RoleMenuMapping();
                          //to get the next ID
                          string EntityName = (db as IObjectContextAdapter).ObjectContext.CreateObjectSet&lt;RoleMenuMapping&gt;().EntitySet.Name;
                          Int32 nextval = new Assyst.PanERP.Common.Common().getNextSequence(EntityName);
                          RoleMapping.RoleMenuMappingId = nextval;
                          RoleMapping.RoleId = permissions.RoleId;
                          RoleMapping.MenuId = rm.Id;
                          RoleMapping.BusinessUnitId = 1;
                          RoleMapping.MenuAdd = (rm.Add == true ? 1 : 0);
                          RoleMapping.MenuDelete = (rm.Delete == true ? 1 : 0);
                          RoleMapping.MenuModify = (rm.Modify == true ? 1 : 0);
                          RoleMapping.MenuView = (rm.View == true ? 1 : 0);
                          RoleMapping.MenuImport = (rm.Import == true ? 1 : 0);
                          RoleMapping.MenuExport = (rm.Export == true ? 1 : 0);
                          RoleMapping.MenuRestrictedView = (rm.RestrictedView == true ? 1 : 0);
                          RoleMapping.MenuBulkUpdate = (rm.BulkUpdate == true ? 1 : 0);
                          RoleMapping.MenuBulkDelete = (rm.BulkDelete == true ? 1 : 0);
                          RoleMapping.MenuSpecial1 = (rm.Special1 == true ? 1 : 0);
                          RoleMapping.MenuSpecial2 = (rm.Special2 == true ? 1 : 0);
                          RoleMapping.MenuSpecial3 = (rm.Special3 == true ? 1 : 0);
                          RoleMapping.MenuSpecial4 = (rm.Special4 == true ? 1 : 0);
                          RoleMapping.MenuSpecial5 = (rm.Special5 == true ? 1 : 0);
  
                          db.RoleMenuMapping.Add(RoleMapping);
                      }
                  }
  
                  db.SaveChanges();
  
                  ViewBag.RoleId = new SelectList(db.Role, "Id", "Code");
                  ViewBag.Module = new SelectList(db.Module, "ModuleId", "ModuleName");
                  ViewBag.ScreenType = new[] { new SelectListItem { Text = "Select", Value = "select" }, new SelectListItem { Text = "Master", Value = "1" }, new SelectListItem { Text = "Report", Value = "2" }, new SelectListItem { Text = "Transaction", Value = "3" } };
  
                  return View("Index");
              }
          }
          catch (Exception ex)
          {
              Elmah.ErrorSignal.FromCurrentContext().Raise(ex);
              return Json(new { Result = "ERROR", Message = ex.Message });
          }
      }
  </code></pre>