That's a strange one Tom. I'm guessing they put in HTML, style or a script without closing it properly.
I suggest you change the course format settings to show one section per page only. That might help you identify the section that houses the bad source and maybe you can fix it.
Say you can't fix it, but you have identified the section, and that you are using a version of Moodle that supports the recycle bin. Then delete the section and its contents. Create a new section and restore the items.
I suggest you change the course format settings to show one section per page only. That might help you identify the section that houses the bad source and maybe you can fix it.
Say you can't fix it, but you have identified the section, and that you are using a version of Moodle that supports the recycle bin. Then delete the section and its contents. Create a new section and restore the items.