I might be too early, because not even the Release Notes of 7.6.778 are out.
But I got an error in the log of one of my devices (only one not the other):
13344 46.306 ERROR opw_app::managers::item_manager:724 > failed to load compromised sites list, getting new one from web. opw-opvault\src\key.rs:155 bad signature
13344 46.569 ERROR opw_app::managers::item_manager:729 > opw-opvault\src\key.rs:155 bad signature
13344 49.926 ERROR opw_app::managers::item_manager:230 > fn on_update_watchtower() error: opw-opvault\src\key.rs:155 bad signature
I tried to restart 1Password some times but it looks like it has corrupted itself during the installation.
I hope this is one more time a rare condition
1Password Version: 7.6.778
Extension Version: 188.8.131.52
OS Version: Windows 10 2004
Sync Type: my.1password.com/Dropbox