Yep disregard the /wp-content/.htaccess file thing.
The problem is this: This particular Web Host is blocking the Server/Website IP Address from being retrieved by BPS Pro (see personal note to myself) and you will need to enter the Server/website IP address manually in the Plugin Firewall .htaccess file. The Server/website IP address will also be blocked on the BPS Pro System Info page by this web host.
Allow from env=whitelist
Allow from ursula-hanisch.de
Allow from [the server/website IP address is missing here due the Host Server blocking this]
IPv4 and IPv6 IP addresses found by using the BPS Pro Pro-Tools DNS Finder tool.
(personal note: maybe implement this DNS method to get the IP address in the Plugin Firewall/Setup Wizard depending on # of cases – so far only 1 web host is known to be problematic).
The IPv4 IP address for this site is: 81.169.145.164
The IPv6 IP address for this site is: 2a01:238:20a:202:1090::144
Try adding the IPv4 IP address first. If that does not work then add the IPv6 IP address.
This web host is: Strato