I have installed and configured your plugin on a local installation of wordpress 3.9 successfully.
However, I tried this morning to update my production website. Everything went smoothly with woocommerce (2.1.8) and other plugins but I am facing a problem with "Weight based shipping" plugin.
"Create additional configuration" button is never showing (it was on my local install).
And the first time I try to save parameters, it says they are saved but they appear they are not saved. Second save is OK - not sure both are related, as I may have had that one on my local install too but I am not 100% sure.
However, I can't add any other configurations as the button is not showing...
BTW, good job with this feature, I wish other plugins have this functionality too.
I have tried lots of things, including deactivating all plugins and switching theme with no luck.
Any pointers where to look at?
Might this be server related?