Encountered "The checkoutCreate mutation failed due to an unknown error." in development environment

[kuleyu]

Unhandled Runtime Error

One unhandled runtime error found in your files. See the list below to fix it:

Error in function eval in ./node_modules/shopify-buy/index.js:3983

The checkoutCreate mutation failed due to an unknown error.

./node_modules/shopify-buy/index.js:3983

  3981 |     }
  3982 |
> 3983 |     return Promise.reject(new Error("The " + mutationRootKey + " mutation failed due to an unknown error."));
  3984 |   };
  3985 | }
  3986 |

Any help please? Thanks