Blogger structure problem blogposting(4)


please friend i have problem with my blog structure which says blogposting(4) error please how can i fix this issue i need help code to fix this please.

and i have other problems with the pagespeed insight whenever i run it it says magnify Java, CSS, Enable compressor etc.

i will be happy if my request is granted



@Innocent_Cyril try this tutorial to remove all the error -