This is a browser requirement. You need to work with your host to setup SSL for your site. Once done, follow the following guide:
Basically once SSL is setup, you change your board path in constants.php to be HTTPS instead of HTTP.
Do the following:
Disable all 3rd-party resources (plugins/applications)
Put a default Invision theme in place
Ensure your site is working
BACKUP your software and database.
Download 4.7.6 manually
Put PHP 8.0.x in place
Upload/upgrade to 4.7.6
Test your site.
Login to the ACP and go through the Marketplace onboarding and link your MP-purchased resources (if any)
Update those resources (do not enable any)
Test your site
If all good, enable any 3rd party resources one at a time and test each time.
