It’s hard to debug only seeing a portion of your code.
For starters, you’ve got two <?php opening tags at the top which would certainly cause an error. But I think that’s leftover from your copy and paste.
- Look at your php server log which will tell you what file and line number the error is occurring.
- Put the following in your
wp-config.phpfile which will print all errors in your browser. Then you won’t have to access the php log directly.
Code to add:
define( 'WP_DEBUG', true );