Currently PrefixSearch is broken:
http://lookup.dbpedia.org/api/search/PrefixSearch?QueryString=berl returns empty result.
But /KeywordSearch is OK:
This is a regression.
I have installed our version available at http://downloads.dbpedia-spotlight.org/dbpedia_lookup/ with 2015_10 model under lookup.dbpedia-spotlight.org and it just works
You can also use our Docker. Just run:
docker run -p 1111:1111 -it dbpedia/lookup java -jar /opt/lookup/dbpedia-lookup-3.1-jar-with-dependencies.jar /opt/lookup/2015-10/
I will check with our support what is happening with our server.