Reported on Stack Overflow: http://stackoverflow.com/questions/26300190/oai-import-dspace
Items harvested into DSpace via OAI apparently don't have a submitter set. This causes a null pointer exception when adding the item to the Solr-based OAI core. From SO:
This error seems to be caused by:
So either you have an item who doesn't have a submitter, meaning that getSubmitter causes the NPE, or that there is a submitter, but that it doesn't have an email, meaning that getEmail will trigger the NPE.