Issue Summary

Pretty links which are created on on-prem instances, get broken when the targeted page is moved to another space. 
Pretty links are not created on Cloud instances, they are migrated from the on-prem instances. However, they are supported in Cloud for the sake of backward compatibility.

Steps to Reproduce

1. Create a page (page A) in an on-prem instance and Publish it.
2. You should be redirected to the view mode of that page (page A) and you can see that the page created is in pretty link format. Example:
   • https://my-example-site.atlassian.net/wiki/display/SPACEKEY/Page+Title
   • 
3. Copy that link/URL, create a new page (page B), and paste it on that page.
   • Please note that when you paste that link on the page (page B), it converts it to Smart Link in the first place. 
   • In order to replicate the issue, we shouldn't use Smart Link.
   • Therefore, after you paste the link, press Ctrl+Z and the link will be reverted to a regular link.
   • The link should look in the format shown in the screenshot below. Publish the page (page B). 
   • {}
4. Go to the first page (page A) that you created (You can use the link that you just pasted).
5. You should be able to access it. 
6. Now migrate the Confluence to the Cloud.
7. After you migrated the Confluence to the Cloud, move the page (page A) (the first page you created) to another space.
8. Go to the page (page B) where you pasted the first page's (page A) link. 
9. Click on the link that you pasted.
10. You will be redirected to the Page not found page and you will get the error below:
    • 

    • Page Not Found
      The page you were trying to reach could not be found: it may have been renamed or moved to another space, or the name you requested may be incomplete. 

      In Other Spaces
      The page you were looking for may have moved to another space: 

Expected Results

It is expected to be redirected to page A when the link is clicked.

Actual Results

Page not found error is raised.

Workaround

We can edit the pretty links manually to Cloud links format which includes the space key and the page id to make them work.