Hi All,

While creating a new image in Media section exception comes "Sequese conatains more than one matching element".

Stack trace is as follow:

[InvalidOperationException: Sequence contains more than one matching element]
System.Linq.Enumerable.Single(IEnumerable`1 source, Func`2 predicate) +4474156
Umbraco.Framework.Persistence.RdbmsModel.Mapping.<>c__DisplayClass4.<MapVersion>b__2(TypedAttribute sourceAttrib, Attribute destAttrib) +416
Umbraco.Framework.Persistence.RdbmsModel.Mapping.ModelToRdbmsMapper.MergeMapCollections(IEnumerable`1 source, ICollection`1 destination, Action`2 mapInPlace, Func`2 mapWithOutput, Action`2 afterMap, Func`3 extraComparison) +1055
Umbraco.Framework.Persistence.RdbmsModel.Mapping.ModelToRdbmsMapper.MapVersion(TypedEntity source, NodeVersion destination, Node masterNode, AbstractLookupHelper lookupHelper, AbstractMappingEngine masterMapper) +656
Umbraco.Framework.Persistence.RdbmsModel.Mapping.ModelToRdbmsMapper.MapTypedEntityForRevision(TypedEntity source, NodeVersion destinationVersion, AbstractLookupHelper lookupHelper, AbstractMappingEngine masterMapper) +699
Umbraco.Framework.Persistence.RdbmsModel.Mapping.ModelToRdbmsMapper.MapFromRevision(Revision`1 source, NodeVersion destination, AbstractLookupHelper lookupHelper, AbstractMappingEngine masterMapper) +114
Umbraco.Framework.Persistence.RdbmsModel.Mapping.ManualMapperv2.Map(Object source, Type sourceType, Type destinationType) +822
Umbraco.Framework.TypeMapping.AbstractMappingEngine.MapToIntent(Object source) +258
Umbraco.Framework.Persistence.NHibernate.NhSessionHelper.MapAndMerge(Revision`1 entity, MappingEngineCollection mappers) +1114
Umbraco.Framework.Persistence.NHibernate.RevisionRepository.PerformAdd(Revision`1 revision) +1718
Umbraco.Hive.ProviderSupport.AbstractRevisionRepository`1.AddOrUpdate(Revision`1 revision) +1713
Umbraco.Hive.ProviderGrouping.RepositoryGroupExtensions.Add(IEnumerable`1 repositories, Revision`1 item, Uri idRoot) +232
Umbraco.Framework.Tasks.ApplicationTaskManager.ExecuteInCancellableTask(Object eventSource, T taskItem, String preActionTaskTrigger, String postActionTaskTrigger, Action execution, Func`2 preActionEventArgs, Func`2 postActionEventArgs, IFrameworkContext frameworkContext) +276
Umbraco.Hive.ProviderGrouping.RevisionRepositoryGroup`2.ExecuteInCancellableTask(IRevision`1 entity, String preActionTaskTrigger, String postActionTaskTrigger, Action execution) +339
Umbraco.Hive.ProviderGrouping.RevisionRepositoryGroup`2.AddOrUpdate(Revision`1 revision) +217
Umbraco.Cms.Web.Editors.AbstractRevisionalContentEditorController`1.ProcessCreate(TEditorModel model, Boolean isRevisional) +1646
Umbraco.Cms.Web.Editors.AbstractRevisionalContentEditorController`1.CreateNewForm(CreateContentModel createModel) +1143
lambda_method(Closure , ControllerBase , Object[] ) +130
System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +264
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +39
System.Web.Mvc.<>c__DisplayClass15.<InvokeActionMethodWithFilters>b__12() +129
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +826378
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +826378
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +826378
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +826378
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +826378
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +826378
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +314
System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +825600
Umbraco.Cms.Web.Mvc.ActionInvokers.ControllerExtenderActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +361
System.Web.Mvc.Controller.ExecuteCore() +159
System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +335
System.Web.Mvc.<>c__DisplayClassb.<BeginProcessRequest>b__5() +62
System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +20
System.Web.Mvc.<>c__DisplayClasse.<EndProcessRequest>b__d() +54
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +469
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +375

Thanks in Advance

Balesh Kumar