From Shopp Documentation

The following lists include links to articles with solutions to frequently encountered problems with Shopp. Most of these issues are related to factors outside of what can be controlled with Shopp's code and must be resolved depending on the operating system, hosting services configuration and WordPress setup, such as installed plugins.

Error Logging
To aid in identifying issues, it can be helpful to turn on Error Logging. Any code-level errors that are produced are saved to a log file that can be given to a Shopp support team member and give clues to more quickly identify problems in individual Shopp installations.

Installation & Setup Issues

• Fatal Error When Activating
• Installing the cURL Library for PHP
• Installing the GD Library for PHP
• Web Hosting PHP5 Support
• Phpinfo File
• IIS Hosting Issues
• Suhosin PHP Extension Issues
• Activates With No Menu
• Activation Fails With Blank Page
• CURLPROTO_FILE Cannot Be Activated
• Find Full File Path
• When Auto Update Fails
• Blank Page
• No Base of Operations or Target Markets

Plugin Compatibility Issues

• Shopp Plugin Compatibility
• Plugins Breaking JavaScript
• Permalink Redirect Manager
• WP Super Cache

Performance Issues

• Images Randomly Not Loading

Upload Issues

Cart Issues

Layout & Style Issues