I'd recommend you to create an issue in the Tracker (https://tracker.moodle.org), providing all the possible details to reproduce the problem, linking it back/forth with this discussion, so everybody knows.
I've performed a quick search, and all I've been to find is MDL-43092 where some action was applied in a theme. But not likely to be the same issue you are commenting above.
Testing and QA
Moodle 2.8 bug
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