Wordpress Network htaccess rewrite causes internal loop

[davidsword]

Spam bots and bad links flood /wp-content/* with bad requests causing 404. In a clean Wordpress network (on Ubuntu 16.04.2, Apache 2.4.18, PHP 7.1) These 404's go in a redirect loop, flooding error logs.

There's a very well written and detailed explanation of problem and an offered solution here:

​https://gist.github.com/JustThomas/141ebe0764d43188d4f2

in short, he suggests adding

RewriteCond %{REQUEST_URI} !^/wp-(content|admin|includes).*$

above

RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]

or removing the question mark in the RewriteRule solve this problem.