In this section we look at the most common technical problems and solutions


CORS error (widget isn’t loading)

Access to manifest at https://sandbox-widget.mrcr.io/img/favicon/light/site.webmanifest' from origin https://sandbox-exchange.mrcr.io has been blocked by CORS policy: No Access-Control-Allow-Origin header is present on the requested resource.

  • Solution #1: Please ensure that you are not trying to run the widget in another iFrame. Opening the Mercuryo widget in another iFrame is not possible at this time.

  • Solution #2: Change the domain in the widget settings. This can be done by opening the dashboard and navigating to "My Widgets":

- Sandbox: https://sandbox-exchange.mrcr.io

- Production: https://exchange.mercuryo.io


Error 403. What does this mean?

sandbox-partners.mrcr.io, sandbox-exchange.mrcr.io and api-sandbox.mrcr.io are only available if your IP address has been added to a whitelist. Please ensure that you are using a whitelisted IP. IP addresses require whitelisting to ensure the security of these systems.


What is the request limit?

Usually no more than 5000 requests in 5 minutes.

Contact us if you need to increase the number of requests per minute.


What should I enter in the Domain field when I set up my first widget?


Do you have any recommendations for the frame size in which the widget will open?

It is designed so that all the information you need is always in view for all screen sizes. Outside the screen is usually the footer. That's why we don't have size recommendations, because we think it should be ok for all screen sizes.


Buy button is not available

The buy button may be inaccessible in cases where the wrong address has been entered or autofilled. The buy button may also be inaccessible if a user has not yet agreed to the terms and conditions.


Signature is invalid error

Signatures are used to identify and access wallet addresses, protecting against use by unauthorised parties. Wallet address signatures are calculated using the following algorithm:

  • signature = sha512(address+secret), where + concatenation operation.

  • Take the address to which we will buy cryptocurrency (thisismyaddress).

  • In the partners' admin panel search for secret (123123123).

  • Open SHA512 hash calculator, paste thisismyaddress123123123 in the field and get crypto-wallet address signature (helloworld).

  • In the partners’ widget URL add signature https://exchange.mercuryo.io?signature=helloworld

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