Please, after installing this plugin everything work correctly but now i can't edit new products! Thank you for your suggestion
I need a bit more information.
What version of QC are you running? What version of productAttributes have you installed? Do you get any error messages? Can you ADD attributes? Can you EDIT attributes? Can you ADD new products? Can you EDIT any products? And if so, can you assign attributes?
It looks to me like you've copied the products_list.tpl template file into the admin templates folder instead of (or maybe as well as?) the default templates folder. Check that you haven't done the same thing with other template files that should have gone into the default templates folder. Put the original products_list.tpl back - either from a backup you made before installing productAttributes, or re-download QC and get an original file from there. Do the same with any other templates put in the wrong place.