0 reset(): Argument #1 ($array) must be of type array, null given

I get this error when I make a group booking. First I can give the number of participants
After enter I get warnings (annex 1) and when i want to go to invoicing i get the error (annex 2)0 reset(): Argument #1 ($array) must be of type array, null given

Hello

What version of the extension you are using? Could be because something with the setup or old version

Please submit a support ticket sending us super admin account of your site and link to the page so that we can check it

Regards,

Tuan