Strange backup message

Hi,

I have already posted a post in the Koko Analytics Forum, but the error is conditionally to be requested on your plugin. Please see this topic: https://ww.wp.xz.cn/support/topic/error-message-in-backup/.

“… I’m getting the following error message when I do a backup with BackWPup. Your koko plugin is also used on another identical page without this error message. Why is that and what does the error message mean? …”

Thx in advance.