Issue: Problem when editing articles

1) Expected, you can disable this by checking "Do NOT create a redirect when renaming this page". If you don't check this box, it will create a clone with the old title so existing links to the old title won't break.
2) This is unexpected, but you can check AdminCP > Wiki URL Manager to see if it lists any pages that are duplicates. If it does, you'll have to handle them on a case-by-case basis and either rename one, or delete one.

1 - It helped, thanks! I used that Lite-version creates a common redirect-thread when "Do NOT create a redirect..." is not ticked, and do not expect that the Premium version creates a complete clone Thank you for your attention!