User becomes not logged in at product page?

[munvera]

Hi,

 

I have logged in to user account in my shop. It shows my user name at top right, means I have logged in.

 

When I click to the product page, which allow me to see the product details and add to cart, I saw my top right become  Login | Register instead of user name. Then, when I back to product list page, it shows my user name at top right again. 

 

Is this causes "Impossible add product to the cart" ? Any hints to fix it? Thanks in advance. 

 

 

Regards,

Munnie

[Rolige]

Try to remember the most recent changes in your shop, this error can be caused by a custom module, modification in core files, overrides, etc, etc