Received an error from the server

An error occured

Mapping types: IContent -> ContentItemDisplay Umbraco.Core.Models.IContent -> Umbraco.Web.Models.ContentEditing.ContentItemDisplay

Destination path: ContentItemDisplay

Source value: Umbraco.Core.Models.Content

EXCEPTION DETAILS

AutoMapper.AutoMapperMappingException:

Mapping types: IContent -> ContentItemDisplay Umbraco.Core.Models.IContent -> Umbraco.Web.Models.ContentEditing.ContentItemDisplay

Destination path: ContentItemDisplay

Source value: Umbraco.Core.Models.Content

at Umbraco.Web.Editors.ContentController.GetById(Int32 id) at lambdamethod(Closure , Object , Object[] ) at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>cDisplayClass10.9(Object instance, Object[] methodParameters) at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken) --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Web.Http.Controllers.ApiControllerActionInvoker._0.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)

System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.SqlDataReader.TryConsumeMetaData() at System.Data.SqlClient.SqlDataReader.get_MetaData() at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, SqlDataReader ds, Boolean describeParameterEncryptionRequest) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource1 completion, Int32 timeout, Task& task, Boolean asyncWrite) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) at Umbraco.Core.Persistence.PetaPocoCommandExtensions.<>cDisplayClass4.3() at Umbraco.Core.Persistence.FaultHandling.RetryPolicy.ExecuteAction[TResult](Func1 func) at Umbraco.Core.Persistence.Database.<Query>d__71.MoveNext() at System.Collections.Generic.List1..ctor(IEnumerable1 collection) at System.Linq.Enumerable.ToList[TSource](IEnumerable1 source) at Umbraco.Core.Persistence.Repositories.VersionableRepositoryBase2.GetPropertyCollection(Sql docSql, IEnumerable1 documentDefs) at Umbraco.Core.Persistence.Repositories.ContentRepository.ProcessQuery(Sql sql) at Umbraco.Core.Cache.DefaultRepositoryCachePolicy2.GetAll(TId[] ids, Func2 getFromRepo) at Umbraco.Core.Persistence.Repositories.RepositoryBase2.GetAll(TId[] ids) at Umbraco.Core.Services.ContentService.GetAncestors(IContent content) at Umbraco.Web.Models.Mapping.ContentModelMapper.AfterMap(IContent content, ContentItemDisplay display, IDataTypeService dataTypeService, ILocalizedTextService localizedText, IContentTypeService contentTypeService) at Umbraco.Web.Models.Mapping.ContentModelMapper.<>cDisplayClass37.0(IContent media, ContentItemDisplay display) at AutoMapper.TypeMap.

What I'm missing while upgrading ? Please help, thanks