Confluence Analytics events fail with a NullPointerException

2015-12-10 10:26:42,429 ERROR [analyticsEventProcessor:thread-1] [analytics.client.listener.ProductEventListener] run Failed to send analytics event com.atlassian.analytics.api.events.MauEvent@8434fcf8 
com.atlassian.cache.CacheException: com.atlassian.util.concurrent.LazyReference$InitializationException: java.lang.NullPointerException 
at com.atlassian.cache.ehcache.DelegatingCache.get(DelegatingCache.java:101) 
at com.atlassian.confluence.cache.ehcache.DefaultConfluenceEhCache.get(DefaultConfluenceEhCache.java:46) 
at com.atlassian.confluence.cache.ConfluenceMonitoringCache.get(ConfluenceMonitoringCache.java:49) 
at com.atlassian.analytics.client.serialize.EventSerializer.hashEmailPropertyForMauEvent(EventSerializer.java:149) 
at com.atlassian.analytics.client.serialize.EventSerializer.access$900(EventSerializer.java:34) 
at com.atlassian.analytics.client.serialize.EventSerializer$2.get(EventSerializer.java:138) 
at com.atlassian.analytics.client.serialize.EventSerializer$2.get(EventSerializer.java:75) 
at com.atlassian.analytics.client.listener.ProductEventListener$1.run(ProductEventListener.java:117) 
at com.atlassian.sal.core.executor.ThreadLocalDelegateRunnable.run(ThreadLocalDelegateRunnable.java:34) 
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) 
at java.util.concurrent.FutureTask.run(FutureTask.java:266) 
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) 
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) 
at java.lang.Thread.run(Thread.java:745) 
Caused by: com.atlassian.util.concurrent.LazyReference$InitializationException: java.lang.NullPointerException 
at com.atlassian.util.concurrent.LazyReference.getInterruptibly(LazyReference.java:149) 
at com.atlassian.util.concurrent.LazyReference.get(LazyReference.java:112) 
at com.atlassian.util.concurrent.ResettableLazyReference.get(ResettableLazyReference.java:87) 
at com.atlassian.analytics.client.hash.BcryptAnalyticsEmailHasher.hashInternal(BcryptAnalyticsEmailHasher.java:45) 
at com.atlassian.analytics.client.hash.BcryptAnalyticsEmailHasher.hash(BcryptAnalyticsEmailHasher.java:40) 
at com.atlassian.analytics.client.serialize.EventSerializer$1.load(EventSerializer.java:65) 
at com.atlassian.analytics.client.serialize.EventSerializer$1.load(EventSerializer.java:62) 
at com.atlassian.cache.ehcache.LoadingCache.getFromLoader(LoadingCache.java:145) 
at com.atlassian.cache.ehcache.LoadingCache.loadValueAndReleaseLock(LoadingCache.java:100) 
at com.atlassian.cache.ehcache.LoadingCache.get(LoadingCache.java:76) 
at com.atlassian.cache.ehcache.DelegatingCache.get(DelegatingCache.java:96) 
... 13 more 
Caused by: java.lang.NullPointerException 
at java.io.Reader.<init>(Reader.java:78) 
at java.io.InputStreamReader.<init>(InputStreamReader.java:113) 
at org.apache.commons.io.IOUtils.copy(IOUtils.java:1906) 
at org.apache.commons.io.IOUtils.toString(IOUtils.java:778) 
at org.apache.commons.io.IOUtils.toString(IOUtils.java:759) 
at com.atlassian.analytics.client.hash.reader.RemoteHashingInstructionsReader.readInstructions(RemoteHashingInstructionsReader.java:27) 
at com.atlassian.analytics.client.hash.BcryptAnalyticsEmailHasher$HashingInstructionsResettableLazyReference.create(BcryptAnalyticsEmailHasher.java:154)
at com.atlassian.analytics.client.hash.BcryptAnalyticsEmailHasher$HashingInstructionsResettableLazyReference.create(BcryptAnalyticsEmailHasher.java:144)
at com.atlassian.util.concurrent.ResettableLazyReference$InternalReference.create(ResettableLazyReference.java:140) 
at com.atlassian.util.concurrent.LazyReference$Sync.run(LazyReference.java:321) 
at com.atlassian.util.concurrent.LazyReference.getInterruptibly(LazyReference.java:143) 
... 23 more