normally there should be no problem using bild.de when running pi-hole.
Funny enough when calling bild.de you will be redirected to the “Why can’t I see bilde.de” page.
There’s a very simple way around that without whitelisting any pages…
First of all: I do not know why this solution works. I am myself working in the IT business (Senior test engineer) but maybe one of the pi-hole developers can answer this problem…
But now for the solution:

open bild.de: You will be presented with the bild.de blocking page…
now disable pi-hole for let’s say 30 seconds
now open bild.de again within the time-period of pi-hole being disabled. this will work, of course :wink:
after the expiration of the given time period open bild.de again and you will see that…
…bild.de will never be blocked again!

This worked for me using
a) Firefox (60.0.1 / 64bit / Win 10 Pro 1803 build 17134.81)
b) Firefox (version ? / 32bit / Android 6)
c) Chrome (66.0.3359.181 / 64bit / Win 10 Pro 1803 build 17134.81)
d) Chrome (66.0.3359.158 / 32bit / Android 6)
Regards
deomaki