http://forum.ait-pro.com/forums/topic/error-installing-bp-pro-after-using-bp-free/#post-117
This is a very common problem that occurs when using the WordPress Upload Zip installer (PclZip) for first time installations of BPS Pro (or other plugins as well).
Issue/Problem: Fatal Errors when upgrading from BPS free to BPS Pro using the WordPress Upload Zip installer (PclZip).
Solution (short version): Use FTP or use your Web Host Control Panel File Manager and rename the /bulletproof-security1/ (bulletproof-security2, bulletproof-security3,…) plugin folder name back to just /bulletproof-security/ (removing any numbers that have been appended to the /bulletproof-security/ plugin folder name by PclZip). Go to the WordPress Plugins page and click the Activate link under BulletProof Security Pro plugin. In some cases you may only need to refresh/reload your Browser on the WordPress Plugins page to activate the BPS Pro plugin.