An error occurred while processing your PayPal payment. Please contact the store

I’ve added credentials to the ‘WooCommerce PayPal Express Checkout Gateway’ Plug-in. When I try and place an order I get the message: ‘Payment error: An error occurred while processing your PayPal payment. Please contact the store owner for assistance.’

Paypal is set to ‘Live’

The orders show up in my orders window but no payment is taken.

I use Paypal Express on another site (non-WP site) and all works fine there.

Status:

### WordPress Environment ###

Home URL: https://www.mtfu.co.uk
Site URL: https://www.mtfu.co.uk
WC Version: 2.6.3
Log Directory Writable: ?
WP Version: 4.5.3
WP Multisite: –
WP Memory Limit: 256 MB
WP Debug Mode: –
WP Cron: ?
Language: en_GB

### Server Environment ###

Server Info: Apache/2.4.18 (Unix)
PHP Version: ? 5.5.37 - We recommend a minimum PHP version of 5.6. See: How to update your PHP version
PHP Post Max Size: 64 MB
PHP Time Limit: 0
PHP Max Input Vars: 1000
cURL Version: 7.19.7
NSS/3.19.1 Basic ECC

SUHOSIN Installed: –
Max Upload Size: 64 MB
Default Timezone is UTC: ?
fsockopen/cURL: ?
SoapClient: ?
DOMDocument: ?
GZip: ?
Multibyte String: ?
Remote Post: ?
Remote Get: ?

### Database ###

WC Database Version: 2.6.3
:
woocommerce_sessions: ?
woocommerce_api_keys: ?
woocommerce_attribute_taxonomies: ?
woocommerce_downloadable_product_permissions: ?
woocommerce_order_items: ?
woocommerce_order_itemmeta: ?
woocommerce_tax_rates: ?
woocommerce_tax_rate_locations: ?
woocommerce_shipping_zones: ?
woocommerce_shipping_zone_locations: ?
woocommerce_shipping_zone_methods: ?
woocommerce_payment_tokens: ?
woocommerce_payment_tokenmeta: ?
MaxMind GeoIP Database: ? The MaxMind GeoIP Database does not exist - Geolocation will not function. You can download and install it manually from https://dev.maxmind.com/geoip/legacy/geolite/ to the path:

### Active Plugins (22) ###

LayerSlider WP: by Kreatura Media – 5.0.2
Advanced iFrame: by Michael Dempfle – 7.1
Contact Form Builder: by WebDorado – 1.0.17
Simple Custom CSS and JS: by Diana Burduja – 1.6
Duplicator: by LifeInTheGrid – 1.1.12
Envira Gallery Lite: by Thomas Griffin – 1.3.5.8
Equivalent Mobile Redirect: by uniquelylost – 3.1
FooBox Free Image Lightbox: by FooPlugins – 1.0.9
Foo Gallery: by FooPlugins – 1.2.9
Google Analytics Dashboard for WP: by Alin Marcu – 4.4.7
Insert PHP: by Will Bontrager Software
LLC  – 1.2

NextGEN Facebook (NGFB): by JS Morisset – 8.31.1-1
Per page head: by Erik von Asmuth – 1.3
PHP Browser Detection: by Mindshare Studios
Inc. – 3.1.8

Revolution Slider: by ThemePunch – 4.3.1
UpdraftPlus - Backup/Restore: by UpdraftPlus.Com
DavidAnderson – 2.12.13.22

WooCommerce Weight Based Shipping: by dangoodman – 4.1.4
WooCommerce PayPal Express Checkout Gateway: by Automattic/WooCommerce – 1.0.4
WooCommerce: by WooThemes – 2.6.3
Yoast SEO: by Team Yoast – 3.2.4
WP Construction Mode: by SmartCat – 3.01
WP-Spreadplugin: by Thimo Grauerholz – 3.9.20

### Settings ###

Force SSL: –
Currency: GBP (￡)
Currency Position: left
Thousand Separator: ,
Decimal Separator: .
Number of Decimals: 2

### API ###

API Enabled: ?

### WC Pages ###

Shop Base: #3078 - /the-store/
Basket: #2992 - /basket/
Checkout: #2993 - /checkout/
My Account: #2994 - /my-account/

### Taxonomies ###

Product Types: external (external)
grouped (grouped)
simple (simple)
variable (variable)

### Theme ###

Name: RT-Theme 18
Version: 1.9.3
Author URL: https://themeforest.net/user/stmcan
Child Theme: ? – If you're modifying WooCommerce on a parent theme you didn't build personally
then we recommend using a child theme. See: How to create a child theme

WooCommerce Support: ?

### Templates ###

Overrides: rttheme18/woocommerce/archive-product.php
rttheme18/woocommerce/cart/cart.php version 2.1.0 is out of date. The core version is 2.3.8
rttheme18/woocommerce/cart/cross-sells.php
rttheme18/woocommerce/content-product.php version 2.5.0 is out of date. The core version is 2.6.1
rttheme18/woocommerce/content-product_cat.php version 2.5.2 is out of date. The core version is 2.6.1
rttheme18/woocommerce/global/wrapper-end.php
rttheme18/woocommerce/global/wrapper-start.php
rttheme18/woocommerce/loop/loop-end.php
rttheme18/woocommerce/loop/loop-start.php
rttheme18/woocommerce/loop/price.php
rttheme18/woocommerce/single-product/product-image.php version 2.0.14 is out of date. The core version is 2.6.3
rttheme18/woocommerce/single-product/related.php
rttheme18/woocommerce/single-product/tabs/additional-information.php
rttheme18/woocommerce/single-product/tabs/tabs.php
rttheme18/woocommerce/single-product/title.php
rttheme18/woocommerce/single-product/up-sells.php
rttheme18/woocommerce/single-product-reviews.php

: Learn how to update outdated templates

https://www.ads-software.com/plugins/woocommerce/