We updated the Cornerstone plugin (including the full X package) for a client and we ran into some trouble. Everything seemed to work fine until we tried to edit an item. The Cornerstone logo shows up and then just sits there. I noticed the following error in the (browser) console:
"typeerror: cannot read property 'indexof' of undefined" in getStack()
And before that it complains about JSON not being formatted correctly (I checked the response in Chrome's Network tab and, indeed, it was a blank response).
Note: I did a rollback on the plugin so I don't have the exact error messages lying around anymore. I could provide them if it's really necessary..
We updated Cornerstone from 1.3.3 to 2.16 - a big jump - so I think this may be the cause of the issue. I'd like to see if I can install incremental updates and avoid the issue. But where can I find the individual updates? Wordpress only offers to install the latest version.