HD Quiz doesn’t do any redirects, so this message is likely a symptom
ERR_TOO_MANY_REDIRECTS is an error generated by your browser, not your site, so unfortunately even enabling
WP_DEBUG in WordPress would not help us.
Without more information, the only suggestion I can make at this point is to do the generic WordPress debug steps to make sure the issue isn’t caused by something esle.
1) Temporarily change themes. It is recommended to change to a default WordPress theme (such as any of the twenty-twentys) and then check the quizzes to see if fixed. If the issue is solved, then we know that the issue was caused by your theme.
2) If the above does not help, then disable all plugins EXCEPT HD Quiz and check the quizzes again. You can then re-enable each plugin one-by-one until the issue returns.
Please let me know if the above helps or not. If you still have the issue I can continue to help you further and to try and get to the bottom of this