Images are not displayed in Drupal

In case of problems with displaying images on the site (images are visible on the page, but they cannot be enlarged or opened in a new window), check the file sites/default/files/.htaccess and eliminate unsupported options (for example, replace the directive Options +FollowSymLinks on Options +SymLinksIfOwnerMatch, delete +ExecCGI etc.).

The problem can be easily found and diagnosed with developer tools in the browser.