I am working on Woocommerce plugin because there is a problem there. I tried to create a variable option product by Woocommerce and every time I choose an attribute and click "Save Attribute" button, it keeps spinning and never ending. I want to dig into the source code of this button to customize something but don't know which is its location. Can you guys let me know which is it? and if anybody has hit this problem, can you please give me some suggestions on fixing this?

Thank you very much and hope to hear from you guys as soon as possible.