Unable to click on element of dropdown list with errror "element not interactable"

HI there,
could some one help me on this case
i have an dropdown list as below: Imgur: The magic of the Internet

i want to select by timeslot by xpath, value of timeslot comes from variable:

//*[@id=“availableTimeSlot”]//ul/li[@value="%s"]

to use Test Object from katalon
I need to cast xpath string of timeslot to Test Object via this code:

public class Timeslot {

	public static def TestObject returnXpathOfSelectedTimeslot(String selectorType, String selectorValue) {
		TestObject to = new TestObject()
		to.addProperty(selectorType, ConditionType.EQUALS, selectorValue)
		return to
	}

	public static def String getTimeslotXpathByValue(int timeslot) {
		TestObject timeslotObject = findTestObject('Object Repository/reservationHomePage/Timeslots/timeslotByValue')

		String timeslotString = timeslotObject.findPropertyValue("xpath")

		return  String.format(timeslotString, timeslot)
	}
}

note: after casting, the properly xpath is returned, wait for element present ok but can’t click to it,

ON TESTCASE

int timeslot = 1900

WebUI.click(findTestObject(‘Object Repository/reservationHomePage/Timeslots/pleaseSelect’))

WebUI.delay(1)

WebUI.waitForElementPresent(Timeslot.returnXpathOfSelectedTimeslot(“xpath”, Timeslot.getTimeslotXpathByValue(timeslot)), 3)

WebUI.click(Timeslot.returnXpathOfSelectedTimeslot(“xpath”, Timeslot.getTimeslotXpathByValue(timeslot)), FailureHandling.STOP_ON_FAILURE)

WebUI.closeBrowser()


ERROR detail:

test Cases/SelectTimeslots/tc1 FAILED.
Reason:
com.kms.katalon.core.exception.StepFailedException: Unable to click on object ''
	at com.kms.katalon.core.webui.keyword.internal.WebUIKeywordMain.stepFailed(WebUIKeywordMain.groovy:64)
	at com.kms.katalon.core.webui.keyword.internal.WebUIKeywordMain.runKeyword(WebUIKeywordMain.groovy:26)
	at com.kms.katalon.core.webui.keyword.builtin.ClickKeyword.click(ClickKeyword.groovy:86)
	at com.kms.katalon.core.webui.keyword.builtin.ClickKeyword.execute(ClickKeyword.groovy:67)
	at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:56)
	at com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords.click(WebUiBuiltInKeywords.groovy:604)
	at com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords$click$4.call(Unknown Source)
	at tc1.run(tc1:27)
	at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194)
	at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119)
	at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:331)
	at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:322)
	at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:301)
	at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:293)
	at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:227)
	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:114)
	at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:105)
	at com.kms.katalon.core.main.TestCaseMain$runTestCase$0.call(Unknown Source)
	at TempTestCase1555657238908.run(TempTestCase1555657238908.groovy:21)
Caused by: org.openqa.selenium.ElementNotVisibleException: element not interactable
  (Session info: chrome=73.0.3683.103)
  (Driver info: chromedriver=2.43.600210 

just big note: when i use this: driver.findElement(By.xpath(’//*[@id=“availableTimeSlot”]//ul/li[@value=“1900”]’)).click()
It can work ok
thank in advance!

Why not skip all of the casting business and just use WebDriver like this? Do you have a requirement to use the Object Repository and the WebUI methods? If not, just stick with what works!

hi Brandon,
its ok so far for me,
i just thinking about any problem when converting to object repository
anyway, i will tick it works
thanks!