When I go to ‘bank mode’…it is unaccessable…says to update antivirus. Which I have done and rebooted. According to my avast antivirus…both definitions and program are uptodate. Thank you for any help you can give me. Love this feature.
I believe I may have solved the issue. Re-set the settings to original and voila…was able to access a “new bank mode window”. Happy camper now 
For some reason…my bank mode is not working once again. Even the sort of ‘backdoor’ relief I found yesterday is no longer available. The Bank Mode app for want of a better word, still says “update antivirus” on it and I have checked and my avast antivirus is up todate. New definitions were this morning. I tried rebooting but still no change. It says the program is up todate as well. Can anyone please suggest what I should try next? Thank you.
Have you tried re-installing Avast Secure Browser.
First save your bookmarks. Go to Bookmarks>Bookmark Manager>three dots> Export Bookmarks
Oh. and do a system Restart (not shutdown/startup) after installation.
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.
Avast has offered a separate tool to totally remove the Secure Browser if the above instructions don’t work.
You can find that tool here, https://forum.avast.com/index.php?topic=230288.msg1531315#msg1531315
Thanks for the advice. I have discovered that all I have to do is go to settings…advanced…restore to original defaults and bank mode re-appears. It sometimes disappears again but I just repeat and there it is. Think I will let sleeping dogs lie lol Thanks again.