Hello I am using odoo 12 and getting this error when valided payement in POS:

​Uncaught TypeError: Cannot read property 'fields' of undefined 
https://casathos.com/web/content/11783-8ec1c42/point_of_sale.assets.js:390 
Traceback:
TypeError: Cannot read property 'fields' of undefined
at child.load_server_data (https:// casathos.com /web/content/11783-8ec1c42/point_of_sale.assets.js:390:485)
at child.load_server_data (https:// casathos.com /web/content/11783-8ec1c42/point_of_sale.assets.js:476:358)
at Object.<anonymous> (https:// casathos.com /web/content/11783-8ec1c42/point_of_sale.assets.js:511:6)
at Object.<anonymous> (https:// casathos.com /web/content/8025-292a2a3/web.assets_common.js:802:681)
at fire (https:// casathos.com /web/content/8025-292a2a3/web.assets_common.js:796:299)
at Object.fireWith [as resolveWith] (https:// casathos.com /web/content/8025-292a2a3/web.assets_common.js:801:198)
at Object.deferred.<computed> [as resolve] (https:// casathos.com /web/content/8025-292a2a3/web.assets_common.js:803:56) 
at Object.<anonymous> (https:// casathos.com /web/content/8025-292a2a3/web.assets_common.js:3558:10)
at Object.<anonymous> (https:// casathos.com /web/content/8025-292a2a3/web.assets_common.js:802:681)
at fire (https:// casathos.com /web/content/8025-292a2a3/web.assets_common.js:796:299)

Can someone help?