"Client authentication failed" when I try to set up my account in the new PayPal module in sandbox mode

[dostoyevski]

The new paypal module does not allow me to configure the sandbox mode. I put the module in sandbox mode, I click connect user, I follow the steps that PayPal tells me, I enter the data of the sandbox account, I click connect, it shows me a message that it was connected successfully, and then I give it to return to prestashop. And then when it comes back it shows me the message "client authentication failed". With the old module I also had a little problem and that is that I had to go back to the prestashop window before finishing the process with paypal, but it connected me. Now with the new module the paypal window opens in a separate tab and I have no chance to do what I did before opening the prestashop window. In short, I can't configure it in sandbox mode. In live mode I keep doing it the way I did in the old module and everything is fine.

All the best.

[seNNNz0rel]

Any updates regarding the issue? Have you managed to fix it? I'm having the same issue.

[AddWeb Solution]

Hi,

• Double-check that you're using the correct sandbox API credentials (Client ID and Secret) from your PayPal developer account. 
• Check that your sandbox app has the necessary permissions to perform the actions required by your Prestashop store.
• Confirm that you have configured the correct return URLs in your PayPal developer account and in the Prestashop module. The return URL must match the one set in your PayPal app.
• Clear your browser's cache and cookies, as stale data can sometimes cause authentication issues.
• Check for any updates to the PayPal module for Prestashop. If an update is available, install it. If the problem persists, you might consider reinstalling the module.
• Check your server logs for any error messages or issues that could be related to the "client authentication failed" message.

If the issue persists after trying the above steps, it may be a technical problem on PayPal's end. Contact PayPal's support for assistance with sandbox configuration issues.

Thanks!