Issue with Cross-sell function

I am having an issue with the cross sell function. I had tried to add to cart the cross sell bundle that I had set up in the cross sell tab but it showed me an error message “an error occurred. please try again.”. Then I even tried to add the bundle from the pop up notification in the cart page and it showed me an error too. Do help me out on this. Thank you.

I am using wordpress and woocommerce. The wordpress website link is https://magift.my/. You can open it and try to purchase from the custom made box tab because that’s where I set the cross sell.