Creating 2 spaces with same ID doesn't produce any error

Bug Description

When a user try to create a space in Confluence with the same Space ID as existing space that the user have no access, Confluence will deactivate the "Create" button without any error message.

This could cause confusion to the user as there are no information provided on why it is not possible to create a space.

How to Replicate

1. Create user A with "Create Space" permission
2. Login with user A and create a private space with space ID : A
3. Logout and access Confluence using administrator user
4. Create user B with "Create Space" permission
5. Login with user B and try to create a space with space ID : A

Expected Behaviour

Confluence should throw error message that inform user that it can't create a space using the proposed space id. It is not necessary to inform user that there is a space using the same id, however Confluence should inform why it failed so user could modify it.

Resulted Behaviour

Create button looks active, however there are no indication why Confluence unable to create the space as can be seen in the screenshot below: