Hiding content in drupal 7

Question

Drupal

Hi. Created material attached to the menu. In the right piece of html I registered <?php print render($page['content']);?>. In the .info file, of course, the content region was specified. But here's the problem: material is displayed in the content (checked with a firebug), but it is hidden. That is, the material on the page is not visible except for its name. How to solve this problem?
Thank you in advance.

Answer 1

Thank you all for your help. The parent block was set to color:#ffffff. This was the problem. Not careful again.

Answer 2

Maybe in the block settings (admin/structure/block) the "Page content" block has not been moved to the "Content" area?