molan on "Woocommerce cart page no longer viewable"

We are running the latest version of Woo (2.6.4) with a Sage Gateway and have recently been hit with a new problem.

Our 'view cart' page appears to be blank and not viewable. It's possible to add items to the basket and they are definitely there (because we get messages if we try to add something twice) but the page seems to have gone.

The site header is visible but not the contents, shipping info etc.

The site has been running quite happily for 5-6 years so it must be something that's been generated from a recent Woo or Sage gateway update i think.

Can you post a link to your site?

http://www.bassgear.co.uk/

Hm, appears to be a php issue of some kind, that stops generating the page cold when it comes to the cart.

Try enabling WP_DEBUG or checking your PHP error log (Your host would know for sure where it is, but it's often in the root directory of your site: error_log) and sharing what you find.

Are you running any WooCommerce extensions?

Here's what the PHP error log said:

bassgear.co.uk [Tue Aug 02 16:53:36 2016] [error] [client 82.18.70.184:33179] AH01215: PHP Waing: Parameter 1 to W3_Plugin_TotalCache::ob_callback() expected to be a reference, value given in /home/sites/bassgear.co.uk/public_html/wp-includes/functions.php on line 3549: /home/sites/bassgear.co.uk/public_html/index.php
bassgear.co.uk [Tue Aug 02 16:53:38 2016] [error] [client 207.46.13.137:34049] AH01215: PHP Waing: Parameter 1 to W3_Plugin_TotalCache::ob_callback() expected to be a reference, value given in /home/sites/bassgear.co.uk/public_html/wp-includes/functions.php on line 3549: /home/sites/bassgear.co.uk/public_html/index.php
bassgear.co.uk [Tue Aug 02 16:53:42 2016] [error] [client 207.46.13.100:37352] AH01215: PHP Waing: Parameter 1 to W3_Plugin_TotalCache::ob_callback() expected to be a reference, value given in /home/sites/bassgear.co.uk/public_html/wp-includes/functions.php on line 3549: /home/sites/bassgear.co.uk/public_html/index.php
bassgear.co.uk [Tue Aug 02 16:53:45 2016] [error] [client 66.249.76.53:39131] AH01215: PHP Waing: Parameter 1 to W3_Plugin_TotalCache::ob_callback() expected to be a reference, value given in /home/sites/bassgear.co.uk/public_html/wp-includes/functions.php on line 3549: /home/sites/bassgear.co.uk/public_html/index.php

This all looks like it's something to do with W3 page caching but I tried disabling the plug in and it didn't make any difference.

We run quite a few Woo extensions - I can make a list if it helps?