i am getting this error when trying to execute sample webviewTest.txt. Firefox opens but quits unexpectedly. attached logs.Could you please help me.

$ pybot --variable platform:firefox webviewTest.txt

webviewTest

[ WARN ] Keyword 'Capture Page Screenshot' could not be run on failure: AttributeError: 'NoneType' object has no attribute 'save_screenshot'
Search "robotframework-anywherelibrary" in google | FAIL |
Parent suite setup failed:

error: [Errno 61] Connection refused

[ WARN ] Keyword 'Capture Page Screenshot' could not be run on failure: AttributeError: 'NoneType' object has no attribute 'save_screenshot'
webviewTest | FAIL |
Suite setup failed:
error: [Errno 61] Connection refused

Also suite teardown failed:
AttributeError: 'NoneType' object has no attribute 'quit'

1 critical test, 0 passed, 1 failed

1 test total, 0 passed, 1 failed