[Plugin: Better WP Security] problem by blocking attackers

That will happen if you’ve renamed your wp-content with existing content (it’s one of the reasons it is recommended not to do so).

My suggestion is to create a rewrite rule of your own that would redirect anything from wp-content/uploads to your new content directory/uploads.

Hello,
I have done that, But it still has problem with old removed plugins and files.
Is it possible that you add new option for 404 detection that ignore search engine’s cached requests? (eg https://webcache.googleusercontent.com)

[ Please do not bump, that’s not permitted here. ]