empty file encountered when attempting to update .htaccess

I’m getting a lot of critical issues every few seconds it would seem with the following error:

empty file encountered when attempting to update .htaccess

There appear to be around 200,000 of these in the logs.

Twice today I’ve had to overwrite the .htaccess file on the server as it was cut off midway through the ban list (see below) and this was causing a 500 error on the server.

	RewriteCond %{HTTP_USER_AGENT} "LinksCrawler" [NC,OR]
	RewriteCond %{HTTP_USER_AGENT} "LinksManager\.com_bot" [NC,OR]
	RewriteCond %{HTTP_USER_AGENT} "linkwalker" [NC,OR]
	Rewrit

Additionally, not sure if this is related, but when trying to update settings I get the following error:

server_ips[0] is not a valid IP address.

I was attempting to adjust settings having seen comments on this issue: https://wordpress.org/support/topic/empty-file-encountered-when-attempting-to-update-apache-config-file-2/