The "expand" functionality for the filetypes/filetypeslist popup does not work when using it every after attempt. First one works, second attempt does not, third one works, forth one does not, and so on....
Steps to replicate:
1. Create a course.
2. Turn editing on.
3. Add an assignment activity.
4. On the assignment settings page, scroll down to Submission types. Click the Choose botton for "Accepted file types".
5. On the Accepted file types modal/popup, click "Expand" for the first entry.
Result: The contents will expand correctly and selections will be visible.
6. Click the "x" button of the modal/popup. This will show the settings page.
7. While still on the settings page, click again the "Choose" button.
8. The modal/popup will again display. Now click once again the "Expand" link.
You will see that it is not working. The "expand" link when clicked, will not do anything. It will not show the expanded list.
9. Now click again the "x" button of the modal/popup.
10. Repeat steps 7 to 8.
You will see that the "expand" functionality works again.
It was found out that the issue manifests alterately during attempts of closing and clicking the "expand" link.
This issue can be replicated using the following as well:
- mod_workshop on the settings page for the "choose" button at Submission settings / Submission attachment allowed file types.
- qtype_essay on the question settings page for the "choose" button at the Response Options / Accepted file types.