Easy Content Type
Disable Taxonomy Archives Fix must be ticked. Otherwise taxonomy archives (product categories) do not show products.
Easy PayPal Custom Fields
Breaks sessions.
Double add to cart issues
Check your page source for empty background-image (css) properties, or img and link tags with empty src/href attributes. These can cause pages to load multiple times.
Frontpage Category Filter
There is a known conflict with Frontpage Category Filter plugin that messes up variations and sale prices, and there are no known workarounds/configurations at this time.
GoDaddy Hosting
Some users have problems with GoDaddy and PayPal IPN/other gateways such as Authorize DPM. This is purely a hosting problem due to their non-standard security measures. Issues need to be solved with GoDaddy directly, as it is out of our hands.
If you find a fix or a workaround for IPN issues and GoDaddy, please share your experience.
GoDaddy Sessions
A common problem with GoDaddy is that the sessions tmp directly is not writable, causing errors like this. Contact GoDaddy support to resolve these issues.
Losing session data between http and https
Caused by Suhosin and can be fixed by setting:
suhosin.session.cryptdocroot = Off
Pressable hosting
Pressable always resets your password after registering the website. The password you set when registering is not the correct one. You need to use the one sent to you via email that asked you to set a new password.
Replete theme by Kriesi
The theme has options for background images in certain areas of the site, such as, header, content, socket, footer etc. and causes double Add-to-Cart issues.
By default these use url() awaiting a script to tell them what image to use. If no image is used, it defaults to url().
Suhosin
If you notice things like tax rates not saving, Suhosin (a security module in PHP) may be preventing the POST data from being saved or you may be on PHP 5.3.9+ with max_input_vars being limited.
More info at: Problems with large amounts of data not saving.
W3 Total Cache
W3 Total Cache breaks wp-cron that certain extensions need to work properly. This can cause issues with WooCommerce Subscriptions and Follow Ups.
WordPress HTTPS
If using WordPress HTTPS, you may experience issues with the Force SSL setting.
WordPress SEO by Yoast
The setting “Redirect ugly URL’s to clean permalinks” in SEO > Permalinks is known to break the checkout process since it strips the query string. Turn this option Off.
WP Customer Reviews
WP Customer Reviews adds extra HTML information to the Order Complete emails.