After upgrading to Magento 2.1.2 :: posted this on Github, anyone else have similar problems?
Pressed save, and the configurations are gone.
This also happens on a currently saved configurable product, when you go in to view only, then if you click on Save, it removes all configuration products from the configuration. (these were there before).
Solved! Go to Solution.
Apologies peeps - didn't read the known issues:
Issue: Error creating configurable products in 2.1.1 (GITHUB-6424). Workaround: Clear your browser cache after upgrading.