[Plugin: WP-SuperCache] Fatal Error upon Install

I’m trying to install WP-SuperCache on a POWWEB hosted site. Said it couldn’t due to a fatal error. Here’s the code I got in the plugin editor:
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Fatal error: Cannot redeclare wp_cache_add_pages() (previously declared in /hermes/web08/b837/pow.bordway13/htdocs/wp-content/plugins/wp-cache/wp-cache.php:182) in /hermes/web08/b837/pow.bordway13/htdocs/wp-content/plugins/wp-super-cache/wp-cache.php on line 109