UFT throws Invalid class string 0x800401F3 (CO_E_CLASSSTRING)) error while opening GUI Test

When i open GUI test, UFT throws error with below details. Please let me know if anyone has idea on how to solve  it.

source: mscorlib

Target Method: System.Type GetTypeFromProgIDImpl(System.String, System.String, Boolean)

Message: Invalid class string (Exception from HRESULT: 0x800401F3 (CO_E_CLASSSTRING))

 

Stack Trace:

at System.RuntimeType.GetTypeFromProgIDImpl(String progID, String server, Boolean throwOnError)
at System.Type.GetTypeFromProgID(String progID, Boolean throwOnError)
at HP.QTP.Backend.Common.QTInfraUtils.CreateComObject[T](String progId)
at HP.QTP.Backend.Builders.InfoProviders.TestInfoProvider.AdditionalNew(TestInfo& info)
at HP.QTP.Backend.Builders.InfoProviders.TestInfoProviderBase`1.New(String name, String newTestFolder)
at HP.QTP.Backend.Builders.ItemBuilders.TestBuilderBase`2.New(String path, IEntity owner, Boolean performSave)
at HP.QTP.Backend.Builders.ItemBuilders.TestBuilderBase`2.New(String path, IEntity owner)
at HP.QTP.Backend.Builders.ItemBuilders.BuilderBase`2.HP.QTP.Backend.Common.IBuilder.New(String path, IEntity owner)
at HP.QTP.Backend.EntitiesFacade.Managers.EntitiesManagerBase.InternalNew(String path, IEntity owner)
at HP.QTP.Backend.EntitiesFacade.Managers.EntitiesManagerBase.New(String path, IEntity owner)
at HP.QTP.BackEndServices.BackEndManager.<>c__DisplayClass12.<NewTest>b__10(Object dummyCreateInfo)
at HP.UFT.Common.Cache`2.GetOrCreate[TCreationInfo](TIdentifier identifier, Func`2 objectGenerator, TCreationInfo creationInfo)
at HP.QTP.BackEndServices.BackEndManager.NewTest(String testname, Boolean isTempTest)
at HP.QTP.ProjectSystem.QtpProjectService.CreateTestProject(String path)
at HP.UFT.Common.Cache`2.GetOrCreate[TCreationInfo](TIdentifier identifier, Func`2 objectGenerator, TCreationInfo creationInfo)
at HP.QTP.ProjectSystem.QtpProjectService.CreateProject(ProjectCreateInformation info)
at HP.QTP.ProjectSystem.QtpProjectBinding.CreateProject(ProjectCreateInformation info)
at ICSharpCode.SharpDevelop.Internal.Templates.ProjectDescriptor.CreateProject(ProjectCreateInformation projectCreateInformation, String defaultLanguage)
at HP.Utt.ProjectSystem.UttProjectTemplate.CreateProject(ProjectCreateInformation projectCreateInformation)
at HP.QTP.ProjectSystem.Templates.CreateNewQtpProjectCommand.InternalRun()
at HP.Utt.UttCore.UttWrappedCommand.Run()
at HP.Utt.ProjectSystem.UttProjectTemplate.<>c__DisplayClass5.<LoadTemplateData>b__4(ProjectCreateInformation projectCreateInformation, Boolean isSolutionVisible, List`1 selectedTemplateItems)
at HP.Utt.ProjectSystem.UttProjectService.CreateProject(UttProjectCreateInformation cinfo, String newSolutionDirectory)
at HP.UFT.ProjectSystem.UftProjectService.CreateTestingProject(UftProjectCreateInformation createInformation)
at HP.UFT.ProjectSystem.Commands.NewTestingProjectCommand.InternalRun()
at HP.Utt.UttCore.UttWrappedCommand.Run()
at ICSharpCode.Core.Presentation.CommandWrapper.Execute(Object parameter)
at MS.Internal.Commands.CommandHelpers.CriticalExecuteCommandSource(ICommandSource commandSource, Boolean userInitiated)
at System.Windows.Controls.MenuItem.InvokeClickAfterRender(Object arg)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)