Region doesn't show the blocks content I can't see a content of custom block (making by clicking on "Add new block").

I try to add block in region, but region doesn't show the block content. I use different kinds of block("Search form", "Powered by Drupal", etc.) and it doesn't help.

What should i do?
Add new block then yo have to specify whether the block should be visible in all pages or specific pages in the Show block on specific pages save it.
also while assigning the block to any particular region you need to save the block by clicking on save blocks button at the bottom of the blocks page.