Sync with Jira fails in the aftermath of deleting an attachment from an Agility workitem that was synced with Jira already. The sync fails because the sync user has no attachment delete permission in Jira.
Add the Administrator Jira role to the Delete All Attachments default permission scheme to fix this issue.
1. Log on to Jira.
2. Select Settings > Issues > Permission Schemes > Default Permission Scheme.
3. Edit the Delete All Attachments permission and add the Administrator role to it.