Avast Secure Browser blank page

I am running Avast Secure Browser on a PC running a Windows 8. I have uninstalled and reinstalled the programme a number of times but still have the same problem - when I launch the Secure Browser, I get a completely blank screen - absolutely nothing on it.

Hello,
I’m sorry to hear that, would you mind sharing a screenshot of the browser with the blank page? Is it only the page, or the whole browser blank?
Also, share here diagnostic information of your browser please, you can find it using this link secure://settings/diagnosticInfo

Only thing I can suggest right now (if only the page is blank) is to go to settings, section “New Session” and to experiment with this setting

Have you done the following?

Clean install of the Secure Browser:
Maybe it’s time for a clean install of the Secure Browser
Download the installer from here, https://www.avast.com/en-us/secure-browser
Download the Secure Browser Removal tool from here, https://download.avastbrowser.com/avast_secure_browser_uninstall.exe
Save your Bookmarks via the Book Marks Manager if you have custom bookmarks so you can import them when you re-install.
Uninstall Secure Browser via Programs and Features - Reboot
Run the removal tool, reboot, run the installer import your favorites if you saved them.
A video to help with the installation: https://youtu.be/r_VLA0HMLQM
Report back if that’s solved the problem or not.