Steps to reproduce:

• Create Content structure as following:

  |- Test (landing_page)
       |- Source (landing_page)
            |- Article (article)
       |- Target (landing_page)
  
  

• add Custom URL-Alias to 'article' Content:

• Move 'Source' Landing Page below 'Target' Landing Page :

• Go to 'Article' Content 

Result:
'Article' is not accessible - BadStateException is thrown:

Ibexa\Core\Base\Exceptions\BadStateException:
Argument 'id' has a bad state: Unable to load path data, path 'article-alias' is broken, alias with ID '64' not found. To fix all broken paths run the ezplatform:urls:regenerate-aliases command
 

Expected:
1. It should not be possible to break Custom URL Aliases in the above described way
2. Even when a Custom URL Alias is broken - for whatever reason - this should not make it impossible to view & edit the Content in the Backoffice.