bad request when following emailed link

[ThomasWaldmann]

we just wanted to inform you that "asmaps" just said that she/he will come to "Python-Workshop - letsmeet.click-Django Sprint".

Use this link to see all RSVPs:
http://email.letsmeet.click/c/...

Cheers,

Clicking on that link -> bad request.

[mfa]

I clicked on the link in my email and it worked.
In our error-reporting (opbeat) there is no 50x in Django for the last 24h.

[ThomasWaldmann]

bad request is 400.