Steps to reproduce:

1. Install clean version of eZ Platform v2.5.
2. Add any language.
3. Create Article under the eZ Platform folder, name it "test".
4. Add the translation for this Article, leave the values exactly the same.
5. Edit main language version (so eng-GB).
6. Change the title to "test-1".
7. Enter the Article's older URL: ez-platform/test.

Actual result:
404 Exception.

Expected result:
The URL should redirect to the mentioned Article as this is its previous alias.

Note:
The problem will only occur for Content with the following flag:
Make content available even with missing translations Not available

Note2:
As a potential fix: the language mask should be updated for the old alias when updating Content.