Changed name of costumer and now I can't enter in product mangamente in my admin

[Xinito87]

Hi,

 

I have a big problem, I'm managing a Prestashop and I the groups of clients appeared as blank.

 

I filled with names ( visitor ) ( Guest ) and ( Costumer ).

Now I can't enter in the product management page of the products, it's like this thing I changed did something that now my prestashop is running bad.

 

Please can you help ???

 

Thanks a lot.