ChromeDriver can't click an element - always throws 'Element is not clickable' error
ChromeDriver clicking works by simulating a mouse click in the middle of the element's first client rect (or bounding client rect if it doesn't have a first client rect). The easiest way to find out where ChromeDriver is attempting to click is to open the chrome devtools and inspect the element to be clicked right before your click operation is called. Select the element in the inspector and notice the blue box(es) representing the client rects of the element, as pictured below. ChromeDriver will attempt to click the middle of the first one. If ChromeDriver is throwing the 'Element is not clickable' error, it is most likely because that location is not actually clickable by the user. To test, simply place your cursor in the middle of the first client rect youself and see if that location is clickable.
In the case above, the test was attempting to click the anchor element. The anchor is not clickable in this case; only the child image is. Because of a margin-bottom style on the image element, the middle of the anchor element falls outside the clickable image bounds, and thus ChromeDriver throws an error. For more info on how positioning/sizing is determined, see the w3 spec. In the case above, the simple fix is to click the image instead of the anchor.
The 'Element is not clickable' error often occurs in the following situations when a test tries to:
click an anchor whose clickable descendant elements are not within the anchor bounds (as above)
click an element fully or partially under another element
click an element offscreen when a fixed overlay is present (the element will be scrolled into view, but it may be scrolled under the fixed overlay)
click an element that is not clickable in the middle (e.g., some types of convex SVG elements)
ChromeDriver sometimes throws an 'Element is not clickable' error
This most likely occurs because the element's location has changed some time after ChromeDriver determined the element's location but before ChromeDriver actually issues a click at the location.
To determine if this is your problem, catch the exception from the click and immediately print/log the current location and size of the element. Compare that with the location that ChromeDriver reports it attempted to click in the exception and see if they are different. If so, you need to wait for the element to stop moving or try to click again. If not, file a bug with a small test page that can be used to reproduce your problem (even if it only occasionally triggers the problem).
ChromeDriver can't click a moving element
This is not a supported feature of ChromeDriver. If the element eventually stops, wait for that to occur. If the element never stops moving, ChromeDriver does not guarantee the click will be successful.