Hello @Hoellwarth,
The problem is caused by the latest version of Ultimate VC Addons plugin. We’ll fix it in the next theme update. Meanwhile you can add background image with functionality of Visual Composer plugin http://storage5.static.itmages.com/i/15/1022/h_1445518246_8730990_e04c1cb2ab.png .
Regards,
Eva Kemp.