Currently, the Create JIRA Issue dialog (the one in the SFDC VF page) throws an error if some required fields don't have value. This confuses users, so the behavior must be made more user-friendly. Specifically:
1. If the integration cannot create an issue because some required field doesn't have value, the "Review & Create" screen should be shown automatically. In our setup, more than half of scenarios imply filling required fields automatically, so there's no need to show this error - just show the "Review & Create" screen.
2. Our JIRA create screens have many fields - up to 20 sometimes. However, only few of them are typically required. So, for an end user, it is not clear which of 20 fields he/she has to fill. So, please mark required fields in the "Review & Create" screen with red asterisk as this is done in JIRA UI.