Note, these instructions are largely a shameless ripoff of those in MDL-26649 which introduced this regression. This must be tested on all supported browsers. Enable JS Create a new quiz on your site. Whilst in the title area, hit the <return> key Confirm that the page tried to save and the calendar did not open* On the editing page click to expand the 'Timing' section. Hover over the calendar icon next to 'Open the quiz' and 'Close the quiz' and ensure the image is not clickable and that the mouse icon does not change to a hand (this is the default behaviour (in Firefox anyway) when hovering over an input type image (even if it is disabled), this may confuse users who think they can interact with it even though the enable checkbox is not checked). Enable the 'Open the quiz' element by clicking on the 'Enable' checkbox. Click on the calendar icon and ensure the calendar pop-up displays and you can choose a date. Select a date and ensure the select box values populate with this date and the calendar closes. Click on the calendar icon again to display the pop-up and then click on it again to ensure it closes. Click on the calendar icon again to display the pop-up and then click anywhere else on the screen (besides the select boxes) to ensure it closes. Select a day, month and year using the select boxes, then click on the calendar icon and ensure the pop-up is set to this date. Change the date in the select boxes while the calendar pop-up is open and ensure the date changes. Uncheck the 'Enable' checkbox and repeat step 3. Create a new course. On the editing page for the 'Course start date' field repeat steps 3-11 as it is a dateselector element, not a datetimeselector. Create a new database activity and ensure you do not get the JS error 'TypeError: this.calendarimage is null' preventing the rest of JS on the form from loading. Try and break the calendar on Firefox with the firebug console open to spot any JS warnings/errors. Disable JS Create a new quiz on your site. On the editing page ensure there is no calendar icon next to the 'Open the quiz' and 'Close the quiz' fields. Create a new course. On the editing page ensure there is no calendar icon next to the 'Course start date' field.