Not possible to make a payment

[mercadolino]

Hello, I am testing your module, but every time I try to checkout on my eCommerce page I am redirected to mercadopago and I get following message:

¡Uy, no! El producto que querías pagar ya no está
El vendedor tal vez lo movió de lugar o tiene algo mejor.

[csrocha]

@mercadolino , are you using the testing mode (sandbox) or a test user? Please read:

https://www.mercadopago.com.ar/developers/en/related/test-users/

[mercadolino]

Hello, thanks for your response, yes I was using sandbox. but for testing
purposes I also used production mode and the same issue happens to me...

UPDATE: I configured the sandbox mode with the test user credentials I generated but the problem persists.
UPDATE2: when the "¡Uy, no! " page appears by refreshing the page it redirects to mercadopago.

[csrocha]

Please, dont use sandbox. I had troubles last week using it.