RemoteComment.java:27 NPE
roleLevel = comment.getRoleLevel().getName()

Caused by: java.lang.NullPointerException
at com.atlassian.jira.rpc.soap.beans.RemoteComment.<init>(RemoteComment.java:27)
at com.atlassian.jira.rpc.soap.util.SoapUtils.getComments(SoapUtils.java:165)
at com.atlassian.jira.rpc.soap.service.IssueServiceImpl.getComments(IssueServiceImpl.java:407)
at com.atlassian.jira.rpc.soap.JiraSoapServiceImpl.getComments(JiraSoapServiceImpl.java:280)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.axis.providers.java.RPCProvider.invokeMethod(RPCProvider.java:397)
at org.apache.axis.providers.java.RPCProvider.processMessage(RPCProvider.java:186)
at org.apache.axis.providers.java.JavaProvider.invoke(JavaProvider.java:323)
... 47 more

– Sample execution (stacktrace above)
irb(main):051:0> svc.getComments(tok, 'WBTOOL-1740')
SOAP::FaultError: java.lang.NullPointerException
from #<SOAP::Mapping::Object:0xb78f926c>

We upgraded to 3.7 using the upgrade procedure (setup naked install in new MySQL db, did an XML restore, then reindexed for good measure).