UnknownError: null protractor

Question

I am following this tutorial

I followed steps except according this post
instead of

npm install -g protractor

I applied

npm install -g protractor --no-optional

I successfully completed Step 0 - write a test

expect(browser.getTitle()).toEqual('Super Calculator');

However when I try Step 1 - interacting with elements

element(by.model('first')).sendKeys(1);

it gives error:

Using the selenium server at http://localhost:4444/wd/hub
[launcher] Running 1 instances of WebDriver
F

Failures:

  1) Protractor Demo App should add one and two
   Message:
     UnknownError: null
   Stacktrace:
     UnknownError: null
   //... continue stack trace

I can see that I can access dom element by testing:

element(by.model('firstXXX')).sendKeys(1);

then it says,

NoSuchElementError: No element found using locator: by.model("firstXXX")

What could be reason for error message mentioned above:

Message:
     UnknownError: null

Also output from webdriver-manager start console:

16:41:27.526 INFO - Executing: [send keys: null null, [1]])
16:41:27.527 WARN - Exception thrown
java.lang.NullPointerException
        at org.openqa.selenium.remote.server.handler.SendKeys.call(SendKeys.java:49)
        at org.openqa.selenium.remote.server.handler.SendKeys.call(SendKeys.java:1)
        at java.util.concurrent.FutureTask.run(Unknown Source)
        at org.openqa.selenium.remote.server.DefaultSession$1.run(DefaultSession.java:168)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)
16:41:27.530 WARN - Exception: null
16:41:27.658 INFO - Executing: [delete session: 157e0397-52e0-4d03-b8ee-aef453cd83a2])
16:41:28.843 INFO - Done: [delete session: 157e0397-52e0-4d03-b8ee-aef453cd83a2]

Answer 1

You should resolve your problems when you use seleniumAddress, but you can also automate Chrome and Firefox with directConnect, example config is here.