Just updated my wordpress to 4.5 & went to install the plugin & get ‘Are you sure you want to do this’ message. Tried extracting the bb-plugin-pro.zip & manually copying it to wp-content\plugins, but plugin is still not showing on plugins page.
Just purchased my license today & trying to figure out what I can do!
Re-tried extracting/installing & checked there are no nested folders, still no luck. I’ve also checked folder permissions - they are the same as my other plugins. Not sure what else to do
Ok, tried installing a different plugin, same results. I can install automatically from the add plugins page, but no plugins will install from the upload page, nor manually. Does not specifically seem to be a BeaverBuilder issue, but anyone have any ideas?
Resolved the issue… Was due to a server config issue on a machine running WAMP
Glad to hear you figured it out, Ian! And thanks for taking the time to inform us. 
Enjoy!
Ben