Error message "the return value of "net.librec.recommender.RecommenderContext.getSimilarity()" is null" on itemknn about librec

[rburke2233]

You might not have specified rec.similarity.class in your properties file.

[samiravaez]

My problem is solved. I thought the properties file would be called automatically when the algorithms were called, , and I did not specify its path in the command.
Thank you