This is the error I get in the console:
browser-polyfill.min.js:1 Uncaught (in promise) Error: Resource::kQuotaBytes quota exceeded
at browser-polyfill.min.js:1:6375
The solution is simple: just delete all old entries.
But maybe it would be better to have older entries deleted when this happens, or display an alert message.
Not a big issue anyway.
Thanks for the extension!