Screenshot showing the untranslated string using ?uselang=qqx
There is a new “Add another category” button, shown during step “Details”
But there is no way to translate it − using the UW with uselang=qqx shows it is hardcoded and not a MediaWiki system message.
I suppose the relevant system message is [[MediaWiki:Mwe-upwiz-categories-add]]
Version: unspecified
Severity: normal
Attached: