What kind of error is this?

Unable to click on object ‘Object Repository/NVData/img_1’ (Root cause: org.openqa.selenium.ElementNotVisibleException: element not visible
(Session info: chrome=62.0.3202.94)
(Driver info: chromedriver=2.33.506120 (e3e53437346286c0bc2d2dc9aa4915ba81d9023f),platform=Windows NT 10.0.15063 x86_64) (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 0 milliseconds
Build info: version: ‘3.7.1’, revision: ‘8a0099a’, time: ‘2017-11-06T21:07:36.161Z’
System info: host: ‘LAPTOP-N0FHHS2F’, ip: ‘192.168.10.104’, os.name: ‘Windows 10’, os.arch: ‘amd64’, os.version: ‘10.0’, java.version: ‘1.8.0_102’
Driver info: com.kms.katalon.selenium.driver.CChromeDriver
Capabilities {acceptSslCerts: true, applicationCacheEnabled: false, browserConnectionEnabled: false, browserName: chrome, chrome: {chromedriverVersion: 2.33.506120 (e3e53437346286…, userDataDir: C:\Users\DAMIO~1\AppData\Lo…}, cssSelectorsEnabled: true, databaseEnabled: false, handlesAlerts: true, hasTouchScreen: false, javascriptEnabled: true, locationContextEnabled: true, mobileEmulationEnabled: false, nativeEvents: true, networkConnectionEnabled: false, pageLoadStrategy: normal, platform: XP, platformName: XP, rotatable: false, setWindowRect: true, takesHeapSnapshot: true, takesScreenshot: true, unexpectedAlertBehaviour: , unhandledPromptBehavior: , version: 62.0.3202.94, webStorageEnabled: true}
Session ID: 3288e09096c7b9d80dbc42e09ed9738d)

This is an error ‘element not visible’, so to resolve it, please add ‘Wait For Element Visible’ keyword

Hi Vinh ! (one OK, the other not yet)

My object is a TreeView.

It works fine for my first click object (img_1):
[START] - Start action : waitForElementVisible
[INFO] - Finding Test Object with id ‘Object Repository/img_1’.
[START] - Start action : click
[INFO] - Finding Test Object with id ‘Object Repository/img_1’
[INFO] - Clicking on object: ‘Object Repository/img_1’
[PASSED] - Object: ‘Object Repository/img_1’ is clicked on

but
did not work for my second click object (‘a_Teste_Posicional’):

[START] - Start action : waitForElementVisible
[INFO] - Finding Test Object with id ‘Object Repository/a_Teste_Posicional’.
[INFO] - Finding web element with id:‘Object Repository/a_Teste_Posicional’
[WARNING] - Web element with id: ‘Object Repository/a_Teste_Posicional’ not found.
[START] - Start action : click
[INFO] - Finding Test Object with id ‘Object Repository/a_Teste_Posicional’
[FAILED] - Unable to click on object ‘Object Repository/a_Teste_Posicional’
[FAILED] - Unable to click on object ‘Object Repository/a_Teste_Posicional’ not found.

Thanks for your help.

Solved !