We have a critical issue on our Magento 2.0.6 (the same issue was also on 2.0.4) whereby the custom options section of a product no longer displays the custom options we originally added. In other words, they are missing.
Despite this, the options are displaying on the live website for said product but we are unable to make any changes or add new custom options in the backend.
We have two highly customizable products which have more than 100 custom options in total and we need to make changes urgently but are unable do to so whilst the options are missing in the backend.
Any help on this would be much appreciated.