Here is the problem:
I made my theme , and at the and I wanted to add "Featured Image" possibility and I add these two lines in my functions.php
add_theme_support( 'post-thumbnails' ); set_post_thumbnail_size( 649, 245, true );
After that when I try to update some post and click update , it takes me to post.php but blank page.
Then I tried to delete these to lines but still don't working.
It's same to options.php > BLANK
Here is my functions.php
And here is the blog