Only 1 column in home page

Hi!
Some days ago I create a web site using the Theme Oblique. It has worked for some weeks but now the home page has only 1 column of the post instead of 3 as described in the theme.
Can you say me why and how can I return to the original design of 3 columns of the posts in the home page?
I have cancelled all the plug in I don’t use.
Thank you!
Silvershark

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