I not that new to wordpress, however I am new to woocommerce. This happened to me too.
However, I managed to solved the issue. It was due to the Restrictions I set using the Role Scoper plugin. The “Page Reader” for the pages Cart/Checkout/My Account/Order ect… needs to be set to Unrestricted.
I don’t know if your using a similar plugin to restrict access to these pages… you can easily tell if you login as an Administrator and everything functions normally.
Hope this helps.
