I am getting this error trying to view the live previews of the page I am editing on bnwiktionary:
[9d2ddc7a-6a68-4585-8bfb-ba0f96a7e879] Caught exception of type Wikimedia\Rdbms\DBConnectionError
Before this, I got an error mentioning something about a DB cluster when trying to read a page, which went away soon after.