Problem with product entrance, from admin panel side

[sportservis.pl]

Hello.

I have a strange problem with product site  - available from admin panel entrance.

I cannot open products - when I will clik to entrance - presta think, think and after arround 30 sec. opening empty page.

I cannot for this moment add, remove, edit any product in mine shop. Basically all products are available from the page side to view, just all.

 

What is important. Other sections work corectly, like: monitoring, catalogue, just products.. not show the list with products.

Were to try solve it?

Thank you.