I got 'Invalid or deleted object.' from app designer.

I am trying to create a app Test Class with app test framework.

I wrote below code,

classdef TestModelVerificationApp < matlab.uitest.TestCase
    properties
        App 
    end
    methods (TestClassSetup)
        % Shared setup for the entire test class
    end
    methods (TestMethodSetup)
        % Setup for each test
        function launchApp(testCase)
            testCase.App = ModelVerificationApp;
            testCase.addTeardown(@delete,testCase.App);
        end
    end
    methods (Test)
        % Test methods
        function test_bttn_select(testCase)
            % Click Button_Select Button
            testCase.press(testCase.App.Button_Run)
            % Verify selected model has been updated
            testCase.verifyEqual(testCase.App.ListBox_SelectedModels.Items,'test item')
        end 
        
        function unimplementedTest(testCase)
            testCase.verifyFail("Unimplemented test");
        end
    end
end

for test below app. Below is a beginning part of the app, 'ModelVerificationApp'

classdef ModelVerificationApp < matlab.apps.AppBase
    properties (Access = public)
        ModelAdvisorAppUIFigure     matlab.ui.Figure
        ModelAdvisorPanel           matlab.ui.container.Panel
        Button_Run                  matlab.ui.control.Button

And, when I try to test this, I got below error message.

        ================================================================================
        Error occurred in ModelVerificationApp/test_bttn_select and it did not run to completion.
        ---------
        Error ID:
        ---------
        'MATLAB:class:InvalidHandle'
        --------------
        Error Details:
        --------------
        Invalid or deleted object.
        
        Error in TestModelVerificationApp/test_bttn_select (line 24)
        testCase.press(testCase.App.Button_Run)
================================================================================

Anyone can tell me why?

Thanks.

Answer 1

[호동]

Okay,

I've figured it out by myself.

The issue was accured because there was a existing app running.

So, when I tried to get the its handle, it encountered the handle isssue.