Hello, Martijntje,
Thank you for contacting us and for using XStore.
Why do you use the old theme version v.8.0.7 https://prnt.sc/E-tHlGMUUrh5 , but the updated Core plugin? You need to update the theme – https://xstore.helpscoutdocs.com/article/63-theme-update
Please do not update the Core plugin before the theme update.
Kind Regards, 8theme team
