Null pointer exception when using .owl as input

[EmmaGerritse]

Hello,

I was using jRDF2VEC to train embeddings for DBpedia 2015-10, when using the .owl file (http://downloads.dbpedia.org/2015-10/dbpedia_2015-10.owl ), I get the following error:

java -jar jrdf2vec-1.1-SNAPSHOT.jar -graph dbpedia_2015-10.owl
Using 4 threads for walk generation and training.
Using vector dimension: 200
Using depth 4
Generating 100 walks per entity.
RDF2Vec Classic
log4j:WARN No appenders could be found for logger (de.uni_mannheim.informatik.dws.jrdf2vec.RDF2Vec).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
walkGeneration mode is null... Using default: RANDOM_WALKS_DUPLICATE_FREE
Exception in thread "main" java.lang.NullPointerException
        at de.uni_mannheim.informatik.dws.jrdf2vec.walk_generators.base.WalkGeneratorDefault.generateRandomWalksDuplicateFree(WalkGeneratorDefault.java:192)
        at de.uni_mannheim.informatik.dws.jrdf2vec.walk_generators.base.WalkGeneratorDefault.generateWalks(WalkGeneratorDefault.java:157)
        at de.uni_mannheim.informatik.dws.jrdf2vec.RDF2Vec.train(RDF2Vec.java:177)
        at de.uni_mannheim.informatik.dws.jrdf2vec.Main.main(Main.java:407)

Using the .nt file does work though (http://downloads.dbpedia.org/2015-10/dbpedia_2015-10.nt ).

Cheers,