I keep receiving an alert "the database has been terminated" while using safari. Why?

I've been experiencing this same issue with v2.10.0 of the Safari extension and v8.10.4 of the 1Password application.

I keep having a tab open with this error, seemingly at random, and nothing I've tried has helped (tried clearing history and caches, uninstalled and reinstalled extension and application). There doesn't actually seem to be anything wrong with 1Password as I can search and autofill etc. just fine, but it's very annoying when the tab opens.