Receive error: "ERROR: Invalid Payment Method" in Sandbox (Standard) mode

[Heinyken]

Working on a Wordpress site with the Memberpress plugin, using Sandbox credentials:

Heinyken-facilitator [at] gmail com

Go through process of establishing API, signature, etc. from developer.paypal and setting up handshake at sandbox.paypal

After establishing everything, try to make a payment/start membership, and no redirect happens, instead receive an error code: "ERROR: Invalid Payment Method". Not sure what debugging to do.

[Heinyken · Accepted solution]

SOLVED

Leaving this here in case someone in the future has the same problems with Memberpress:

"Your users are seeing this error before getting to the payment screen: ERROR Invalid Payment Method. - This likely means that you have enabled the Customize Payment Methods and left this gateway option unchecked. To fix this, simply uncheck the Customize Payment Methods option altogether, or if you need it to disable other gateway options for your membership, be sure to check this gateway option."

https://docs.memberpress.com/article/138-paypal-sandbox