If you see the 'Invalid captcha' warning on your screen (see above) you have either failed to click the box, proceeded to quickly to logging in after clicking it or selected a wrong image from the grid presented. Simple X out of the warning and follow the process again.
CAPTCHA is a security feature that helps protect websites from spam and abuse. A simple test to tell human and bots apart. It is easy for humans to solve, but hard for “bots” and other malicious software to figure out:
Simply click the box to the left of 'I am not a robot,' wait a few seconds for the spinning wheel to turn into a tick then proceed to click LOGIN.