Like in this post (http://www.shape5.com/component/option,com_smf/Itemid,75/topic,21123.msg83626/#msg83626
) I have the same issue and I have already done what was suggested by mikek : I downloaded the latest versions of the zip file , I replaced the files in the language folder root . I did the same in templates / game_world / vertex / xml / language , but unfortunately I still have the same problem .
As soon as I installed the siteshaper I upgraded joomla to 3.5.1 , I noticed that the English language file is 3.5.0 , may depend on it ? For information, I use both the frontend to the backend in Italian.
PS: I tried to do it all on my local server and without updating joomla it's all right ... maybe it really was the upgrade of the core joomla?