empty cart issue

I have a problem with some of my products, after clicking ‘add to cart’ they do not appear in the cart/checkout pages. some products work, and other do not. I have tried looking for a solution to this, and have tried switching to 2014 theme to see if it still happens, which it does. I have tried switching all other plugins off except woocommerce, but the empty cart problem is still there. Below is the system report gereated by WC If anyone knows of anything that might solve this, or point me in the right direction, it would be much appreciated. I am fairly new to wordpress/woocommerce and am struggling with this. Thanks in advance ??

### WordPress Environment ###

Home URL: https://www.ntdeals.co.uk
Site URL: https://www.ntdeals.co.uk
WC Version: 2.4.13
Log Directory Writable: ? /websites/123reg/LinuxPackage23/ba/th/_k/bath-king.co.uk/public_html/wp-content/uploads/sites/5/wc-logs/
WP Version: 4.4.1
WP Multisite: ?
WP Memory Limit: 64 MB
WP Debug Mode: –
Language: en_US

### Server Environment ###

Server Info: Apache
PHP Version: 5.6.16
PHP Post Max Size: 8 MB
PHP Time Limit: 30
PHP Max Input Vars: 1000
SUHOSIN Installed: –
MySQL Version: 5.5.33
Max Upload Size: 1 MB
Default Timezone is UTC: ?
fsockopen/cURL: ?
SoapClient: ?
DOMDocument: ?
GZip: ?
Remote Post: ?
Remote Get: ?

### Database ###

WC Database Version: 2.4.13
:
woocommerce_api_keys: ?
woocommerce_attribute_taxonomies: ?
woocommerce_termmeta: ?
woocommerce_downloadable_product_permissions: ?
woocommerce_order_items: ?
woocommerce_order_itemmeta: ?
woocommerce_tax_rates: ?
woocommerce_tax_rate_locations: ?

### Active Plugins (3) ###

WooCommerce Colors: by WooThemes – 1.0.6
WooCommerce: by WooThemes – 2.4.13
WordPress MU Domain Mapping: by Donncha O Caoimh – 0.5.5.1
WordPress MU Domain Mapping: by Donncha O Caoimh – 0.5.5.1
WooCommerce Colors: by WooThemes – 1.0.6
WooCommerce: by WooThemes – 2.4.13

### Settings ###

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

### API ###

API Enabled: ?
API Version: 3.0.0

### WC Pages ###

Shop Base: #7 – /shop/
Cart: #8 – /cart/
Checkout: #9 – /checkout/
My Account: #10 – /my-account/

### Taxonomies ###

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

### Theme ###

Name: Headway Base
Version: 3.8.5
Author URL: https://www.headwaythemes.com
Child Theme: ? – If you’re modifying WooCommerce or a parent theme you didn’t build personally we recommend using a child theme. See: How to create a child theme
WooCommerce Support: ?

### Templates ###

Overrides: –

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