makason on "[Plugin: WP-Filebase Download Manager] characters of unexpected output"

After activating WP-filebase, got en error -- the plugin generated 132 characters of unexpected output during activation. If you notice “headers already sent” messages, problems with syndication feeds or other issues, try deactivating or removing this plugin. I tried deactivating and reuploading.

I was not able to create categories because it said, "Database error: Table 'wp_chem.wp_wpfb_files' doesn't existDatabase error: Table 'wp_chem.wp_wpfb_files' doesn't exist."

Using PHP 5.3.3

I assume the plugin didn't instal correctly. What's causing this and how to fix?

Thanks.

https://wordpress.org/plugins/wp-filebase/