No unscribe link in notification mail - easyblog

Hello everybody,

now I have a problem with unsubscribing the blog-abonnement.

First I noticed just now, that the notification-mail contains no unsubscribe link.
I think in germany it is necessary....

And afterwards when I try to sign off the abonnement on the frontpage - when I´m logged in with a registered account - I get the message 500 - see the picture below.

Can you help me?

Thanks a lot in advance. Kind regards
Margitta