Clicking delete selected attempts without attempts being selected on Results|Responses within Quiz Results displays the below error:

Element of type FORM is not supported by the M.util.show_confirm_dialog function. Use A or INPUT

This is reproducible on qa.moodle.net.

Steps to Reproduce
Assumption: Quiz with attempts exists.
Click Quiz.
Click Attempts.
Click Responses in navigation.
Click Delete selected attempts.
Click Yes on confirmation.

Expected - Perhaps screen refreshes. No actions executed.
Actual - Message displays.