作为新手，我尝试使用Nutch与solr索引和爬网单个网站，但出现此错误。，我不知道确切的错误是什么。谁能帮我这个 ？预先感谢。
Segment dir is complete: crawl/segments/20181011155036.
Segment dir is complete: crawl/segments/20181011155140.
Indexer: starting at 2018-10-11 15:54:06
Indexer: deleting gone documents: false
Indexer: URL filtering: false
Indexer: URL normalizing: false
No exchange was configured. The documents will be routed to all index writers.
Active IndexWriters :
SOLRIndexWriter
type : Type of the server. Can be: "cloud", "concurrent", "http" or "lb"
url : URL of the SOLR instance or URL of the Zookeeper quorum
commitSize : buffer size when sending to SOLR (default 1000)
auth : use authentication (default false)
username : username for authentication
password : password for authentication
Indexing 20/20 documents
Deleting 0 documents
Indexing job did not succeed, job status:FAILED, reason: NA
Indexer: java.lang.RuntimeException: Indexing job did not succeed, job status:FAILED, reason: NA
at org.apache.nutch.indexer.IndexingJob.index(IndexingJob.java:152enter code here)
at org.apache.nutch.indexer.IndexingJob.run(IndexingJob.java:235)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at org.apache.nutch.indexer.IndexingJob.main(IndexingJob.java:244)