Shortcode is not recognised, [:] missing

Hello!

I have an annoying error with the plugin. I’m using an Event manager plugin and somehow some events – only some appears on the webpage without recognising it is multilanguage. Like this:
[:en]BodyART Strength[:de]BodyART Krafttraining[:]
it seems that the english section is not closed with the [:]

Strangely if I go to the wordpress admin to edit the page it appears without any problem but on the life site. I tried to delete and redo the event without success.
Strange is that other events works just fine.

What can I do?

Thanks a lot!

The page I need help with: [log in to see the link]