today I updated our test install XWiki from 15.10.3 to 15.10.4. The server is Debian, server is Apache2 with Tomcat9 and Postgresql.
Following How to remove an entry in the navigation bar when related page does not exist? - #8 by jmarkoll and How to remove an entry in the navigation bar when related page does not exist? - #10 by vmassol
Now it is not Ukrainian anymore but Corean language.
샌드박스 테스트 페이지 1 according to Deepl.com is Corean and means
Sandbox Test Page 1 (which is consistant with last pages visited, but not the language!)
As said in the former thread, only English is setup in this installation.