Try a plugin skip/bypass rule for the Riva Slider Pro plugin.
1. Add this skip/bypass rule below to this BPS Custom Code text box: CUSTOM CODE PLUGIN/THEME SKIP/BYPASS RULES: Add personal plugin/theme skip/bypass rules here
NOTE: If your WordPress installation is in a subfolder then add the WordPress subfolder name to the skip/bypass rule. Example: /MyWordPressFolderName/wp-content/plugins/riva-slider-pro/
# Riva Slider Pro skip/bypass rule RewriteCond %{REQUEST_URI} ^/wp-content/plugins/riva-slider-pro/ [NC] RewriteRule . - [S=13]
2. Click the Save Root Custom Code button.
3. Go to the BPS Security Modes page, click the Create secure.htaccess File AutoMagic button and activate Root folder BulletProof Mode again.