Hi,
The upcoming domain name migration to on the Wikimedia Toolforge implies
that OpenRefine users need to update their Wikidata reconciliation
service to the new endpoint:
https://wdreconcile.toolforge.org/en/api
or by replacing "en" by any other Wikimedia language code.
The new home page of the service is at:
https://wdreconcile.toolforge.org/
This new endpoint will be available by default in the upcoming release
of OpenRefine (3.4).
For details about why an automatic migration via redirects is sadly not
possible, see this Phabricator ticket:
https://phabricator.wikimedia.org/T254172
Cheers,
Antonin