I have a very strange and redundant error on the OnePage Checkout of a Magento shop (ver. 188.8.131.52). After step 5 (Payment Information) I have a blank page only displaying the contact e-mail Address. It should show the order overview.
I viewed the console for any errors, checked server side error logs, activated and checked the Magento error log and update the index.php and changed PHP settings to display errors. Nothing! Not one error.
I've also wiped the cache and session files.
I'm totally clueless what the issue could be. I even copied onepage.phtml from base to the theme folder.
Also changed the PHP Version from 5.6.* to 7.0.* and updated memory_limit to 512M and max_execution_time to 600.
Any suggestions what I could try to solve the issue? Thanks in advance.