First I updated the PHP version, then I updated the PHPmyAdmin version, followed by a WordPress/plugin update only to find that my theme wasn’t compatible with any of it. Instead of going and installing the updated theme (none to be found), I updated the look of it. That’s why the images don’t appear for most of the posts. The previous theme didn’t utilize that feature.
I also installed a plugin called SyntaxHighlighter Evolved, that works pretty well when pasting in code snippets.