Could anyone tell me why a sudden my site does not come with

Of a sudden my site does not enter the original window but enters this product page. If you click on the home menu, you will see the main page that was before appearing this page? Have mexi in various places and do not know exactly what causes this page is this way? Does anyone have any suggestions?

Please check template basic settings maybe you have enabled mainbody on frontpage and previously it was only component.