Fogbugz importer fails to create links

 
[16:03:36] ---------------------------
[16:03:36] Importing of Issues started
[16:03:36] Only new Issues will be imported
[16:03:36] Importing issue number 1 : Issue {summary=1st test case d only, type=Bug}
[16:03:36] Importing issue number 2 : Issue {summary=2nd case l only, type=Bug}
[16:03:36] Importing issue number 3 : Issue {summary=3rd case d & l , type=Bug}
[16:03:36] Importing issue number 4 : Issue {summary=relates, type=Bug}
[16:03:36] Importing issue number 5 : Issue {summary=duplicate & relates, type=Bug}
[16:03:36] Importing issue number 6 : Issue {summary=duplicates, type=Bug}
[16:03:36] 6 issues successfully imported
[16:03:36] Importing of Issues finished
[16:03:36] ----------------------------
[16:03:36] 

[16:03:36] Rewriting old issue keys for 6 issues
[16:03:36] Rewritten comment for issue FOGBUGZ-5
[16:03:36] Rewritten comment for issue FOGBUGZ-4
[16:03:36] 

[16:03:36] --------------------------------
[16:03:36] Importing of Issue Links started
[16:03:36] Only new Issue Links will be imported
[16:03:36] Linking 'FOGBUGZ-1' and 'FOGBUGZ-1' as Duplicate
[16:03:36] Linking 'FOGBUGZ-5' and 'FOGBUGZ-3' as Duplicate
[16:03:36] Linking 'FOGBUGZ-4' and 'FOGBUGZ-2' as null
[16:03:36] FAILED: Unexpected failure occurred. Importer will stop immediately. Data maybe in an unstable state
[16:03:36] java.lang.IllegalArgumentException: Name cannot be null.
	at com.atlassian.jira.issue.link.DefaultIssueLinkTypeManager.validateIssueLinkTypeInput(DefaultIssueLinkTypeManager.java:41)
	at com.atlassian.jira.issue.link.DefaultIssueLinkTypeManager.createIssueLinkType(DefaultIssueLinkTypeManager.java:28)
	at com.atlassian.jira.external.ExternalUtils.createOrFindLinkType(ExternalUtils.java:727)
	at com.atlassian.jira.external.ExternalUtils.createIssueLink(ExternalUtils.java:700)
	at com.atlassian.jira.imports.importer.impl.DefaultJiraDataImporter.importIssueLinks(DefaultJiraDataImporter.java:782)
	at com.atlassian.jira.imports.importer.impl.DefaultJiraDataImporter.doImport(DefaultJiraDataImporter.java:143)
	at com.atlassian.jira.imports.importer.impl.ImporterThread.run(ImporterThread.java:21)

# written by PropertiesConfiguration
# Wed Oct 22 16:01:26 EST 2008
project.importJIRA = fogbugz
link.Duplicates = Duplicate
value.sCategory.Bug = Bug
value.sCategory.Schedule Item = Task
value.sCategory.Inquiry = Task
value.sFullName.Brian Lane = Major
value.sPriority.Must Fix = Major
value.sPriority.Fix If Time = Minor
value.sCategory.Feature = New Feature
value.sPriority.Don't Fix = Trivial

[08:56:46] ---------------------------
[08:56:46] Importing of Issues started
[08:56:46] Only new Issues will be imported
[08:56:47] Importing issue number 1 : Issue {summary=1st test case d only, type=Bug}
[08:56:47] Importing issue number 2 : Issue {summary=2nd case l only, type=Bug}
[08:56:47] Importing issue number 3 : Issue {summary=3rd case d & l , type=Bug}
[08:56:47] Importing issue number 4 : Issue {summary=relates, type=Bug}
[08:56:47] Importing issue number 5 : Issue {summary=duplicate & relates, type=Bug}
[08:56:47] Importing issue number 6 : Issue {summary=duplicates, type=Bug}
[08:56:47] 6 issues successfully imported
[08:56:47] Importing of Issues finished
[08:56:47] ----------------------------
[08:56:47] 

[08:56:47] Rewriting old issue keys for 6 issues
[08:56:47] Rewritten comment for issue FOGBUGZ-5
[08:56:47] Rewritten comment for issue FOGBUGZ-4
[08:56:47] 

[08:56:47] --------------------------------
[08:56:47] Importing of Issue Links started
[08:56:47] Only new Issue Links will be imported
[08:56:47] Linking 'FOGBUGZ-1' and 'FOGBUGZ-1' as Duplicate
[08:56:47] Linking 'FOGBUGZ-5' and 'FOGBUGZ-3' as Duplicate
[08:56:47] Linking 'FOGBUGZ-4' and 'FOGBUGZ-2' as related
[08:56:47] Linking 'FOGBUGZ-5' and 'FOGBUGZ-3' as related
[08:56:47] Importing of Issue Links finished
[08:56:47] ---------------------------------
[08:56:47] Flushing issue cache

# written by PropertiesConfiguration
# Thu Oct 23 08:56:26 EST 2008
project.importJIRA = fogbugz
link.Duplicates = Duplicate
link.BugRelation = related
value.sCategory.Bug = Bug
value.sCategory.Schedule Item = Task
value.sCategory.Inquiry = Task
value.sFullName.Brian Lane = Major
value.sPriority.Must Fix = Major
value.sPriority.Fix If Time = Minor
value.sCategory.Feature = New Feature
value.sPriority.Don't Fix = Trivial