(1) may be caused by your current network instability. You can save the coupon as a template on the current page, refresh the page, and then load and save it from the template.
(2) There may be an error in the browser cache, so I suggest you clean the browser cache first.
(3) Because information such as account data needs to be extracted from the server after logging in, when there are many accounts in the A/C set and the number of voucher lines is long, saving will fail. I suggest that you can improve the network speed and computer configuration. If the above methods cannot solve your problem, please consult online customer service.