Noticed the following error in 2.3 only while testing MDL-35398:

Notice: Undefined property: stdClass::$filter in /integration/23/mod/assign/locallib.php on line 2687

Disabling Javascript from the browser produce the above message. Enabling Javascript/ajax from moodle and browser produces error in browser error console.

To reproduce:

1. enable quickgrading in admin
2. create an assignment (the new assignment module)
3. select 'view/grade all submissions' link
4. make changes to the options setting for the quickgrading (options setting at the bottom of the page)
5. depending on the Javascript setting you have, one of the above message will occur.