I installed the new K2 version 9 and now i get every time this. How can i solve the problem. Can someone help me out please

Thank you so much. !!! It solves the problem.

I have same I guess:
Warning: count(): Parameter must be an array or an object that implements Countable in /home/rapigukk/public_html/templates/bemax/html/com_k2/blog-list/item.php on line 228

The master file didnt helped...any idea ?

You've got me stumped.

So I should check from my template this:
bemax/html/com_k2/blog-list/item.php on line 228

with the source K2 template. right ?

I extracted the zip file github.com/getk2/k2/archive/master.zip and checking the folder structure.
Is this in components/com_k2/.......... inside ?

Appreciate your help

Fotis, okey in Summary:

On the homepage is the warning:
Warning: count(): Parameter must be an array or an object that implements Countable in /home/rapigukk/public_html/templates/bemax/html/com_k2/blog-list/item.php on line 228

This is the line 228 on item.php from my template (downloaded):
<?php if($this->item->params->get('itemExtraFields') && count($this->item->extra_fields)): ?>

and in the /components/com_k2/templates/default/item.php is:
<?php if($this->item->params->get('itemExtraFields') && isset($this->item->extra_fields) && count($this->item->extra_fields)): ?>

My questions:
Shall I change from master-template with this on my page ?

Thank you for your help