Get Project Hierarchy error - "Project with id: X is not simplified"

[Nitzan Mass-Ader]

I've been using the /rest/api/2/project/{projectId}/hierarchy endpoint for a while now, and recently I've been getting issues when calling it against a company managed project. 

NotFound: 404 Not Found on GET request for 
"{jira-site-url}/rest/api/2/project/{company-managed-project-id}/hierarchy":
 "{"errors":{}, 
   "errorMessages":["Project with id: {company-managed-project-id} is not simplified."],
   "httpStatusCode":{"empty":false,"present":true}}"

For the record, the errorMessages part also has the project id written in a formatted way for some reason (e.g 12345 -> 12,345) but I'm pretty sure that's not important.

I couldn't find any documentation for this type of error. Some research about the "simplified" part pointed me in the direction that this is to do with team vs. company managed projects, which helped me reproduce it, but not much more. Does anyone know of this error and what might cause it?

[Marc - Devoteam]

Hi @Nitzan Mass-Ader 

Welcome to the community.

I think you have to use API v3 now, se: https://developer.atlassian.com/cloud/jira/platform/rest/v3/api-group-projects/#api-rest-api-3-project-projectid-hierarchy-get 

I would use the call: 

{jira-site-url}/rest/api/latest/project/{company-managed-project-id}/hierarchy