Can't view website after upgrading

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I have got a serius problem.
I had the old version 5.7.3.1. To upgrade to the newest version, I first had to upgrade to 5.7.4.1. I had some problems, but after using the instructions described as “Manual Dashboard Update” herehttp://documentation.concrete5.org/developers/installation/upgradin... everything worked.
Now I have upgraded to the newest version 5.7.5.8 in exactly the same way.
But now I can't view my website. The adress ishttp://www.marieskiks.dk and when you go to the site, you get this message:
An exception occurred while executing 'select count(cID) from MultilingualSections': SQLSTATE[42S02]: Base table or view not found: 1146 Table 'marieskiks_dk_db.MultilingualSections' doesn't exist

What have I done wrong? And what shall I do?