UPDATE: BPS Pro 13+ and BPS 2.0+ versions have a feature called: Setup Wizard AutoFix (AutoWhitelist|AutoSetup|AutoCleanup) that automatically creates plugin and theme whitelist rules and automatically sets up and cleans up caching plugins htaccess code.
Create a plugin Skip/Bypass rule for the Shopp ecommerce shopping cart plugin in BPS Custom Code.
1. Copy the Shopp ecommerce shopping cart plugin skip/bypass rule below to this BPS Root Custom Code text box: CUSTOM CODE PLUGIN/THEME SKIP/BYPASS RULES
2. Click the Save Root Custom Code button.
3. Go to the BPS Security Modes page and click the Root Folder BulletProof Mode Activate button.
Note: If your WordPress installation is a subfolder installation then add your WordPress folder name in the path. Example: /My-WordPress-Folder-Name/wp-content/plugins/shopp/
# Shopp ecommerce shopping cart skip/bypass rule
RewriteCond %{REQUEST_URI} ^/wp-content/plugins/shopp/ [NC]
RewriteRule . - [S=13]