Sometime last year, I built a site using the X theme and Cornerstone.
We attempted to make some revisions to the site this year and discovered that Cornerstone had been updated to a new version. When attempting to add new elements via the interface, we would see the element placeholders, but no text or images would appear even when we would add them. All of the old elements still existed and we could duplicate them without issue.
When saving and viewing the live site, the new sections and elements would be completely missing, no placeholders, no html that the elements were there, nothing.
Are there any reports of compatibility issues with old web pages and the new interface?
