Product variations changed to zeros

Hello,

I made a website while ago (a few months).
Now I logged in to it and wanted to add a product with attributes and variations. But when I try to do that, attributes on attributes page simply don’t add (page reloads, but nothing happens). Also, when I try to add attributes on a product page, it adds only “0” instead of atttributes ( one 0 = one new attribute. image: https://gyazo.com/04fd4412849b573710333d08a819c6db ). On the products that were added while ago attributes are ok, but variations show 0 too.

I think it may be an update of wordpress?
Would really appreciate any help ! Thanks!