In Moodle 2.7 css for wordcensorship filter is missing.
Steps to produce this bug:
1. Enable wordcensorship filter at your Moodle site from Administration > Site administration > Plugins > filters > manage filters. And configure the same.
2. Then add few words (eg- idiot , stupid etc) in your course.
3. You will notice word is not blackout.
But I have check HTML class is applied to it but css is missing from bootstrapbase theme. That's why it is not called in any theme.
Please check attached file for css and add in moodle.css file in Bootstrapbase theme.