When going to the Sales/Orders and viewing an order, the Information tab (default) is blank. View: screenshot
Checked the log and saw this error:
Warning: simplexml_load_string(): Entity: line 2: parser error : XML declaration allowed only at the start of the document in ...wwwroot\app\code\core\Mage\Core\Model\Layout\Update.php on line 450
Warning: simplexml_load_string(): <?xml version="1.0" encoding="UTF-8"?> in ...wwwroot\app\code\core\Mage\Core\Model\Layout\Update.php on line 450
Warning: simplexml_load_string(): ^ in ...wwwroot\app\code\core\Mage\Core\Model\Layout\Update.php on line 450
Was unsure of how to handle so I cleared the var/cache and var/session, turned off the compiler and enabled errors.
That error is gone but this error now appears in the log (and the problem still exists):
CRIT (2): Not valid template file:adminhtml\base\default\template\aitcommonfiles/design--adminhtml--default--default--template--sales--order--view--tab--info.phtml
The file is there and seems fine - it wasn't customized.
Could someone point me in the right direction to troubleshoot and fix?