How can I add an empty project to a new Piority scheme

[Sebastien Denis]

I created a new priority scheme with Low - Medium - High, Medium being the default priority.

I have a JSM project which is empty, with no issue.

When trying to add this project to my new priority scheme, I got the following message:

I don't understand why I must also add Highest and Lowest to my new priority scheme. 

[Kris Dewachter]

Hi @Sebastien Denis ,

Welcome to the Atlassian Community.

The system is asking you to map the old priorities to the new priorities. The fact that you don't have any issues in the project, doesn't matter.

I presume the "Medium" priority appears in both the old and the new scheme? That's why you don't need to map that value.

Best regards,

Kris

[Sebastien Denis]

@Kris Dewachter 

It does the trick, thanks.

However why do I need to do this ? What is the logic behind this ?