CiviCRM Database Upgrade White Screen

Question

I have followed the instructions located on the CiviCRM Website to a fault.

https://docs.civicrm.org/sysadmin/en/latest/upgrade/drupal7/

The files are a fresh install and the Status Page tells me to click here to upgrade:

I go to UPGRADE PAGE a blank white page shows. I have checked the error files/logs i cant see anything relating to the upgrade page.

To Confirm the Title of the page is: "Upgrade CiviCRM to Version 5.13.4"

Thanks,

Answer 1

After hours of trying to figure out the issue, i have been able to fix this by changing the Theme in Drupal.

When i made the Theme into a default theme the upgrade page showed with no issues.