In as many browsers as possible: IE8 IE9 IE10 Firefox Chrome iOS Safari iOS Chrome Android Chrome Android Whatever else you can find Testing instructions: Open a course Turn editing on Click the "Add block..." dropdown Close it (by clicking on it) it again without making a selection Confirm no change Hit enter (keyboard) to open it again Hit enter (keyboard) to close it again Confirm no change Use the mouse to select an item from the "Add block..." dropdown Confirm that it was added Use the keyboard to select an item from the "Add block..." dropdown Confirm that it was added Add a new assignment Set the feedback type to the "Offline grading worksheet" Open the activity View/grade all submissions From the dropdown choose "Download grading worksheet" Confirm that you were prompted to download the file Click cancel Click the dropdown again and change it to the top option Confirm that there was no change, and you weren't promped to download the file again Note: Opera used to not handle some items properly - keyboard IIRC. This may be fixed now they've moved to Blink.