Error 10002 – Security header is not valid appears on the Django Oscar page

The paypal in settings.py is not set up properly, as follows:
PAYPAL_SANDBOX_MODE = True
PAYPAL_CALLBACK_HTTPS = False
PAYPAL_API_VERSION = ‘119’
# These are the standard PayPal sandbox details from the docs – but I don’t
# think you can get access to the merchant dashboard.
PAYPAL_API_USERNAME = ‘sdk-three_api1.sdk.com’
PAYPAL_API_PASSWORD = ‘QFZCWN5HZM8VBG7Q’
PAYPAL_API_SIGNATURE = ‘A-IzJhZZjhg29XQ2qnhapuwxIDzyAZQ92FRP5dqBzVesOkzbdUONzmOU’
PAYPAL_PAYFLOW_VENDOR_ID = ‘xxxxxxxxxxxxxx’
PAYPAL_PAYFLOW_PASSWORD = ‘xXXXXXXXXXXXx’# Standard currency is GBP
PAYPAL_CURRENCY = PAYPAL_PAYFLOW_CURRENCY = ‘GBP’
PAYPAL_PAYFLOW_DASHBOARD_FORMS = True

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