Hi Tim,
Yes, image showing in qa.moodle.net, but not in my project.
What to test where is the problem in my project? Is it better idea to turned off filters and check..... or any idea?
Thanks for informed me about qa.moodle.net.
I think the next test is to work out if it is all questions on your system, or just this one. Can you try making a completely new question with images, and see if that works.
Also, is it only in the combined feedback? What happens if you add an image to a different part of the question?
Hi Tim,
Made new quiz and inserted image in diff portion :
Question text : image showing
General feedback : image showing
Answers : image showing
Combined feedback : image not showing. After inspecting... copy image url then past to new tab. Found error: Sorry, the requested file could not be found. Any idea? Thank you.
It's working for me: 
That equation is an image I added in the 'Feedback for any correct response' for this multiple choice question.
Hi Tim,
Changed to boost theme to see if our custom theme is responsible? Still image does not showing. Then where could be wrong, any guess? Do you using Moodle 3.2.1? Thank you.
Same problem.
is there any idea how to fix this?
thanks