I can reproduce on the latest (current ones on 27th of February) versions of XWiki 15.10.6 and 16.1 with Java 21 not only by visiting Skin page, but copy/paste the below code on Sandbox or any Test pages.
{{attachmentSelector classname="XWiki.XWikiUsers" property="image" filter="png,jpeg,jpg,gif" displayImage="true" buttontext="choose" width="123" cssClass="myCSSClass"/}}
That raises same warning in logs
2024-02-27 11:56:21,842 [http-nio-7635-exec-6 - http:
Note, that if remove displayImage="true" my XWiki console won't have any warnings |