Why do I get a "Fatal error: WooCommerce is not active or not installed" when trying to activate the Prices by User Role plugin, even though WooCommerce is active and installed?

This issue often arises if the folder name for WooCommerce differs from the expected default. During activation, the Prices by User Role plugin attempts to access the file 'woocommerce/woocommerce.php'. If the WooCommerce folder is named differently (e.g., 'woocommerce-2.5.5'), it can lead to the fatal error. 

Please verify the folder name of your WooCommerce installation to ensure it matches the expected path.