Hi @matimediza matimediza
If you are using Mercado Pago – Custom Checkout, your account needs to be homologated!
You can access the configuration at the Mercado Pago – Custom Checkout configuration page. A warning will be displayed at the top of the page with a link, in case you need to homologate your account.
For an alternative solution, you can collect the logs to identify the problem.
At the “Mercado Pago – Custom Checkout” configuration page, go to “advanced settings session” and set “Debug Mode” to ‘Yes’.
Perform a new test payment and check the log. This log is available at Woocommerce’s configuration status page, at a Log tab.
If you find the error below, it indicates that you need to homologate your account:
[create_preference]: mercado pago gave error, payment creation failed with error: Unauthorized use of live credentials