I can't change images
You can check the images via FTP, the problem can be cache.
I've deleted cache of my website, even the browser but not working, apparently is impossible to upload images through the component. The only solution I found is select PNG format in "Server Setting" and then upload the images directly to components/com_activehelper_livehelp/server/domains/1/i18n/en/pictures. Now is working but you know is not the best solution.