Troubleshooting a Blank Page/Oops Error Message
Navigate to Setup > General Settings.
Select the Other tab and then scroll to the bottom of the page.
Tick to enable Display Errors and hit Save.
Now re-perform the steps that previously were creating a blank page. This time instead of a blank page you should see an error message indicating what is causing the issue.
Once you are done, be sure to disable Display Errors again.