For some reason, I get this error when I'm trying to create a new item through Special:NewItem. I searched this error in Google and found nothing. What am I downg wrong? ;(
I use:
MediaWiki 1.30.0
PHP 7.1.11 (apache2handler)
Wikibase Repository cc48ad1 (downloaded usign git)
I was following this instruction — Wikibase/Installation
Please help.