If you are having broken images issue when trying to add media, especially jpeg and png images, on blog posts and text blocks on Live Editor pages, re-install your WordPress from the dashboard. Go to Dashboard >> Updates >> click reinstall now.
In case the issue would persist, please reach out to your web host and have them re-install WordPress at the back end as this issue is normally caused by missing or corrupted WordPress installation.
We also have found a few cases recently on certain web hosting companies deleting these core WordPress files; thus reinstalling WordPress is needed to fix the issue.