Tried on another phone, same thing. I dared press the marked button and it appears it wants me to install Tapatalk. Digging a bit, it appears this is installed on the server (support for Tapatalk), and apparently Martin misconfigured it to appear in German.
Tapatalk is a paid app (costs $3 USD), and I don't see anybody on EmuTalk posting from it (otherwise you would see a lot of posts saying "Sent from my [DEVICE] using Tapatalk 2"). If I could make a suggestion, I'd say just remove it.