I get this error when trying to create a ticket for Jira. I assume that it it pertaining to one of my fields within Salesforce but it doesn't tell me which one exactly. Does that just mean that one of my fields aren't compatible when trying to make the transition to Jira?
I'm coming up against the same issue. Can a feature request be raised to add the field name (as you would see in JIRA or Salesforce, not customfield_12345) to the error messages shown in the Jira Issues visualforce component.