¿Por qué podrá generarse un error de timeout al crear una solicitud de vacación desde el portal?

La solicitud tiene configurada una ruta y funciona bien en un ambiente de desarrollo; pero en Producción genera este error:

System.Data.EntityCommandExecutionException: An error occurred while executing the command definition. See the inner exception for details.
 ---> System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
 ---> System.ComponentModel.Win32Exception: The wait operation timed out 
--- End of inner exception stack trace ---
 at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 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) 
 at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 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 System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) 
 at System.Data.EntityClient.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior) --- End of inner exception stack trace --- 
 at System.Data.EntityClient.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior) 
 at System.Data.Objects.Internal.ObjectQueryExecutionPlan.Execute[TResultType](ObjectContext context, ObjectParameterCollection parameterValues) 
 at System.Data.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption) 
 at System.Data.Objects.ObjectQuery`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator() 
 at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source) 
 at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source) 
 at Aseinfo.Infrastructure.Base.Entity.EntityServiceBase`2.GetEntityById(IdT id, Expression`1[] includes) in c:\vh4\Infrastructure\Base\Entity\EntityServiceBase.cs:line 270 
 at Aseinfo.VH4.Infraestructura.Services.Workflow.AuthorizationWorkflowInstanceConstructor.GenerarInstanciaConActividades(IAuthorizationWorkflowManagedEntity entity) in c:\BuildAgent\work\608d469cc106b504\VH4\Infraestructura\Services\Workflow\AuthorizationWorkflowInstanceConstructor.cs:line 105 
 at Aseinfo.VH4.Infraestructura.Workflow.WorkflowFoundationEngine.InitializeCurrentWorkflowInstance(IAuthorizationWorkflowManagedEntity entity, IAuthorizationWorkflowManagedEntityService entityService) 
 at Aseinfo.Infrastructure.Base.Entity.EntityServiceBase`2.InitializeWorkflowInstance(IAuthorizationWorkflowManagedEntity workflowManagedEntity, IWorkflowEngine workflowEngine) in c:\vh4\Infrastructure\Base\Entity\EntityServiceBase.cs:line 723 
 at Aseinfo.Infrastructure.Base.Entity.EntityServiceBase`2.InitializeWorkflowInEntity(IAuthorizationWorkflowManagedEntity entity, IInstanciaRutaAutorizacion instanciaQueSeReintenta) in c:\vh4\Infrastructure\Base\Entity\EntityServiceBase.cs:line 682 
 at Aseinfo.Infrastructure.Common.Extensions.MvcExtensions.InicializaFlujoAutorizacion(SecuredExtendedControllerBase controller, IAuthorizationWorkflowManagedEntity entity, IAuthorizationWorkflowManagedEntityService service, IInstanciaRutaAutorizacion instanciaQueSeReintenta) in c:\BuildAgent\work\608d469cc106b504\Infrastructure\Common\Extensions\MvcExtensions.cs:line 567

Supongo que es configuración porque en el otro servidor sí funciona, pero no tengo idea de qué es lo que debe estar fallando.