Why does a PayPal payment fail with the message «SSL certificate problem: unable to get local issuer certificate»?

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dmitrii_fediuk (Dmitrii Fediuk) February 7, 2016, 5:19am 2

See also:

Why does a PayPal payment fail with the message «Payment Gateway is unreachable at the moment»?
How to fix the «SSL certificate problem: unable to get local issuer certificate» issue while signing into a Magento Marketplace account on the backend Component Manager screen