Why the default issue type scheme deletes issues project ?

[KMEROVIL]

I'd like to change the Issues Types Scheme of several projects. I order to standardize the issue type scheme, I use the Default Issue Type Scheme, when I have to Archive the project. As the project is link with the default issue type scheme, I can delete the project issue type scheme. 

Because there are all the issue types in the default issue type scheme, my issues do not have to be deleted. However, when I restore the project, I lost all the issues. 

Could you please tell me why the issues are gone?

[Rebekka Heilmann _viadee_ · Accepted solution]

So just to make sure we understand you correctly.

1. You had a project with it's own issue type scheme
2. You changed the projects issue type scheme to the default scheme
3. You archived said project
4. you restored said project

And now the project has 0 issues?

[KMEROVIL]

More or less. Here is the context, the process I followed and the result. 

Context : The organization has too many Issue Type Schemes. So we are trying to standardize them. So i am creating several Issue Type Schemes in order to reduce the sum from 100 to 20. 

Process : When the project has a specific Issue Type Schemes, and it has no activity from 6 months or more, it will be archived. In order to delete it's Issue Type Scheme, I write the issue type, to assign the best Issue Type Schemes generic template to this project, if someone asks us to restore it. To clean the specific Issue Type Schemes, I use the Default Issue Type Schemes to this project, because there are all issue Type, and I am sure we will not loose any data. Cause all the Issue Type are in this Schemes. 

Result : However, when I restore the project, all the issues are deleted. I could not find them anywhere. I changed only the Issue Type Schemes, I did not change the Screen scheme or the fields. So I don't understand why I am loosing data. 

I am operating on Jira Data Center

[Rebekka Heilmann _viadee_]

Have you performed a Project Re-Index as indicated in this article (in the last step): Archiving a project | Administering Jira applications Data Center and Server 9.12 | Atlassian Documentation
?

[KMEROVIL]

This is perfect. This is exactly what I missed. Thanks so much for your Help. 

Have a wonderful day. ;)

[Rebekka Heilmann _viadee_]

If that was the missing piece, please accept my answer so others can see your question has been resolved.