FragDenStaat.de uses letsencrypt for HTTPS certificates. Unfortunately, the standard Java installation doesn't recognize that authority and the reconciliation will be stuck in the "Working" screen. Here's how to fix this.
- Download the cross-signed certificate: https://letsencrypt.org/certs/lets-encrypt-x3-cross-signed.pem.txt
- Import the certificate into the keystore of OpenRefine
keytool -import -alias letsencrypt -keystore /Applications/OpenRefine.app/Contents/PlugIns/jdk1.8.0_60.jdk/Contents/Home/jre/lib/security/cacerts -file ~/Downloads/lets-encrypt-x3-cross-signed.pem.txt