Problem java.lang.NullPointerException occured when trying to process

ov 22, 2017 12:14:34 PM org.archive.crawler.framework.ToeThread recoverableProblem
SEVERE: Problem java.lang.NullPointerException occured when trying to process 'http://www.netarkivet.dk/' at step ABOUT_TO_BEGIN_PROCESSOR in 
 (in thread 'ToeThread #7: http://www.netarkivet.dk/')
java.lang.NullPointerException
        at org.archive.crawler.prefetch.PreconditionEnforcer.considerRobotsPreconditions(PreconditionEnforcer.java:243)
        at org.archive.crawler.prefetch.PreconditionEnforcer.innerProcessResult(PreconditionEnforcer.java:178)
        at org.archive.modules.Processor.process(Processor.java:142)
        at org.archive.modules.ProcessorChain.process(ProcessorChain.java:131)
        at org.archive.crawler.framework.ToeThread.run(ToeThread.java:148)

Nov 22, 2017 12:14:34 PM org.archive.crawler.framework.ToeThread recoverableProblem
SEVERE: Problem java.lang.NullPointerException occured when trying to process 'http://www.netarkivet.dk/favicon.ico' at step ABOUT_TO_BEGIN_PROCESSOR in 
 (in thread 'ToeThread #7: http://www.netarkivet.dk/favicon.ico')
java.lang.NullPointerException
        at org.archive.crawler.prefetch.PreconditionEnforcer.considerRobotsPreconditions(PreconditionEnforcer.java:243)
        at org.archive.crawler.prefetch.PreconditionEnforcer.innerProcessResult(PreconditionEnforcer.java:178)
        at org.archive.modules.Processor.process(Processor.java:142)
        at org.archive.modules.ProcessorChain.process(ProcessorChain.java:131)
        at org.archive.crawler.framework.ToeThread.run(ToeThread.java:148)

Nov 22, 2017 12:14:34 PM org.archive.modules.CrawlURI getPolitenessDelay
WARNING: politessDelay unset, returning default 5000 for http://www.netarkivet.dk/favicon.ico (in thread 'ToeThread #7: http://www.netarkivet.dk/favicon.ico')