Reported in https://moodle.org/mod/forum/discuss.php?d=421358

If you try to create a drag-drop markers question with and SVG background image (which should work, and did work in the past) then when you try to save, it always shows the "The shape you have defined goes out of the bounds of the background image" error.

This is because the file API call to get the size of an image ultimately uses the PHP function getimagesize and that does not support SVG images as far as I can see.

Increasingly, on the web, SVG images are what people are using, so ideally we should fix this in the File API if we can. (Google found https://stackoverflow.com/questions/6532261/how-do-you-get-the-width-and-height-of-an-svg-picture-in-php for me.)