System.ArgumentNullException for issue where EpicLink field is not present

[gggsaige]

Hi I am running into an issue similar to the following but was not able to find the solution

• [System.ArgumentNullException] System.ArgumentNullException: Value cannot be null. Parameter name: key #688
• Unexpected migration error. [System.ArgumentNullException] System.ArgumentNullException: Value cannot be null. Parameter name: field #980
• Issue in Curl Command while preforming the Jira to ADO Migration. #1080

The export process goes well until it hits an unexpected migration:

[I][01:02:02] Connecting to Jira...
[I][01:02:02] Retrieving Jira fields...
[I][01:02:02] Retrieving Jira link types...
[D][01:02:02] Get item count using query: 'project = DEV AND status = Done AND assignee = 712020:313bb74c-3fd7-452c-b208-3974327dbd55 AND type IN (Bug, Story) ORDER BY created DESC'
[I][01:02:03] Export started. Selecting 29 items.
[W][01:02:03] Epic link field missing for config field 'Epic Link'.
[I][01:02:03] Initializing Jira field mapping...
[D][01:02:03] Enumerate remote issues
[I][01:02:03] Processing 1/29 - 'DEV-699'.
[D][01:02:04] Downloaded item.
[D][01:02:04] Rendered field issuetype contains unparsable type Null, using text
[D][01:02:04] Rendered field project contains unparsable type Null, using text
[D][01:02:04] Rendered field resolution contains unparsable type Null, using text
[D][01:02:04] Rendered field workratio contains unparsable type Null, using text
[D][01:02:04] Rendered field customfield_10020 contains unparsable type Null, using text
[D][01:02:04] Rendered field priority contains unparsable type Null, using text
[D][01:02:04] Rendered field customfield_10019 contains unparsable type Null, using text
[D][01:02:04] Rendered field assignee contains unparsable type Null, using text
[D][01:02:04] Rendered field status contains unparsable type Null, using text
[D][01:02:04] Rendered field attachment contains unparsable type Array, using text
[D][01:02:04] Rendered field summary contains unparsable type Null, using text
[D][01:02:04] Rendered field creator contains unparsable type Null, using text
[D][01:02:04] Rendered field reporter contains unparsable type Null, using text
[D][01:02:04] Rendered field customfield_10000 contains unparsable type Null, using text
[D][01:02:04] Downloaded issue: DEV-699 changelog.
[D][01:02:04] Created 10 history revisions.
[D][01:02:04] Mapping revision 0.
[D][01:02:05] Downloaded attachment '11883/image-20250312-131520.png'
[D][01:02:05] Downloaded attachment '11886/image-20250312-150133.png'
[D][01:02:05] Mapped value '[DEV-699] "Product" is missing from the results pages' to field 'System.Title'.
[D][01:02:05] Mapped value '3' to field 'Microsoft.VSTS.Common.Priority'.
[D][01:02:05] Mapped value 'New' to field 'System.State'.
[E][01:02:05] Unexpected migration error.
[System.ArgumentNullException] System.ArgumentNullException: Value cannot be null. (Parameter 'field')
at JiraExport.LinkMapperUtils.AddRemoveSingleLink(JiraRevision r, List1 links, String field, String type, ConfigJson config) at JiraExport.JiraMapper.MapLinks(JiraRevision r) at JiraExport.JiraMapper.MapRevision(JiraRevision r) at JiraExport.JiraMapper.<>c__DisplayClass6_0.<Map>b__2(JiraRevision r) at System.Linq.Enumerable.SelectListIterator2.ToList()
at JiraExport.JiraMapper.Map(JiraItem issue)
at JiraExport.JiraCommandLine.ExecuteMigration(CommandOption user, CommandOption password, CommandOption token, CommandOption url, CommandOption configFile, Boolean forceFresh, CommandOption continueOnCritical):
at JiraExport.LinkMapperUtils.AddRemoveSingleLink(JiraRevision r, List1 links, String field, String type, ConfigJson config) at JiraExport.JiraMapper.MapLinks(JiraRevision r) at JiraExport.JiraMapper.MapRevision(JiraRevision r) at JiraExport.JiraMapper.<>c__DisplayClass6_0.<Map>b__2(JiraRevision r) at System.Linq.Enumerable.SelectListIterator2.ToList()
at JiraExport.JiraMapper.Map(JiraItem issue)
at JiraExport.JiraCommandLine.ExecuteMigration(CommandOption user, CommandOption password, CommandOption token, CommandOption url, CommandOption configFile, Boolean forceFresh, CommandOption continueOnCritical)
[I][01:02:05] Export complete. Exported 0 items (1 errors, 1 warnings) in 00:00:03.

Any ideas on where to begin troubleshooting for this? From what I can see, this is related to some kind of link field not being found on the JIRA project, but the logs don't specify which one.

I've also attached a version of the config.json file

config copy.json

with sensitive names removed.

Thanks in advance.

[Alexander-Hjelm]

Hello @gggsaige !

For reference

• The error happens for the issue "DEV-699" on he first revision.
• The error happens inside this method (The field parameter is null):

  jira-azuredevops-migrator/src/WorkItemMigrator/JiraExport/RevisionUtils/LinkMapperUtils.cs

  Line 44 in 30b7f35

  public static void AddRemoveSingleLink(JiraRevision r, List<WiLink> links, string field, string type, ConfigJson config)

• Presumably, this is the function call:

  jira-azuredevops-migrator/src/WorkItemMigrator/JiraExport/JiraMapper.cs

  Line 264 in 30b7f35

  LinkMapperUtils.AddRemoveSingleLink(r, links, _jiraProvider.GetSettings().EpicLinkField, "Epic", _config);

I also see this warning in the log file:

[W][01:02:03] Epic link field missing for config field 'Epic Link'.

Despite the warning, you do seem to have set the relevant property in your config file:

"epic-link-field": "Epic Link",

The Epic Field field ID is fetched here, but results in a null value or an empty string:

jira-azuredevops-migrator/src/WorkItemMigrator/JiraExport/JiraCommandLine.cs

Line 106 in 30b7f35

jiraSettings.EpicLinkField = jiraProvider.GetCustomId(config.EpicLinkField);

Conclusion

My most credible theory is that the field "Epic Link" perhaps does not exist in your Jira Project "DEV". Could this be the explanation? Have a look at the fields in your Jira project and make adjustments to the config accordingly,

Let me know if this still does not solve your issue, and let us then troubleshoot further.

[gggsaige]

Hey @Alexander-Hjelm thanks for looking into it. That does seem like the most probable cause of it.

However I spoke with our PM who manages the JIRA project, and they said that the epic link field has been deprecated and is not configurable anymore? https://support.atlassian.com/jira-software-cloud/docs/upcoming-changes-epic-link-replaced-with-parent/

Is it possible to skip the epic link migration altogether?

[Alexander-Hjelm]

One idea could be to change the value of the "epic-link-field" config property from "Epic Link" to "Parent" in order to target the new Parent field. You can give it a try, but I am not completely sure.

[gggsaige]

It seems like that will get the export process going, but I suspect doing it this way will cause some errors with actual parent-child ticket linking. I will run the process and report any further issues, if I run into them. Thank you @Alexander-Hjelm I think we can close this one.

[Alexander-Hjelm]

@gggsaige, Sure! Give it a try and let us know if you are still experiencing any issues. Let us keep this issue open. Feel free to use this space to report any further problems or findings :)

The automation will clean issues with no activity for the last 30 days.

[gggsaige]

Hey @Alexander-Hjelm unfortunately a related error popped up:

[D][12:34:13] Mapping revision 1.
[D][12:34:13] Mapped value 'To Do' to field 'System.State'.
[D][12:34:13] Mapping revision 2.
[D][12:34:13] Mapping revision 3.
[D][12:34:13] Mapped value 'gyang@saigetechnologies.com' to field 'System.AssignedTo'.
[D][12:34:13] Mapping revision 4.
[D][12:34:13] Mapping revision 5.
[D][12:34:13] Mapping revision 6.
[D][12:34:13] Mapped value 'Closed' to field 'System.State'.
[E][12:34:13] Unexpected migration error.
[System.InvalidCastException] System.InvalidCastException: Cannot cast Newtonsoft.Json.Linq.JObject to Newtonsoft.Json.Linq.JToken.
at Newtonsoft.Json.Linq.Extensions.Convert[T,U](T token)
at Migration.Common.JsonExtensions.ExValue[T](JToken token, String path)
at JiraExport.JiraItem.get_EpicParent()
at JiraExport.JiraProvider.EnumerateIssues(String jql, HashSet1 skipList, DownloadOptions downloadOptions)+MoveNext() at JiraExport.JiraCommandLine.ExecuteMigration(CommandOption user, CommandOption password, CommandOption token, CommandOption url, CommandOption configFile, Boolean forceFresh, CommandOption continueOnCritical): at Newtonsoft.Json.Linq.Extensions.Convert[T,U](T token) at Migration.Common.JsonExtensions.ExValue[T](JToken token, String path) at JiraExport.JiraItem.get_EpicParent() at JiraExport.JiraProvider.EnumerateIssues(String jql, HashSet1 skipList, DownloadOptions downloadOptions)+MoveNext()
at JiraExport.JiraCommandLine.ExecuteMigration(CommandOption user, CommandOption password, CommandOption token, CommandOption url, CommandOption configFile, Boolean forceFresh, CommandOption continueOnCritical)

Tracing the logs, I believe this is because the parent for this ticket was added after ticket was created, and other changes were made to the ticket. So some revisions don't have a parent value, and thus failing the Epic Link requirement. I wonder if there is a way to 1. skip revisions 2. ignore the epic link?

[Alexander-Hjelm]

Ok! I suspect that it is trying to treat other Parent links as Epic links, and is comparing the issuelinks to the wrong schema.

Probably something we should look into.

[gggsaige]

Thanks @Alexander-Hjelm - for the time being, I found that setting download option to 0 which skips downloading all related tickets, does the trick for us.