I recently followed this migration documentation to update the Prismic Slice Machine from version 0.1.0 to 1.19.1 as part of upgrading our Next.js Prismic Front End. I seemed to have it working in local for the Next.js side and was doing final testing before deployment. In the slice machine UI all our slices were showing in the slice list and our custom types were also listed (page, menu). When I went into the custom page type I saw that non of the slices were assigned to the page type like they were in the Prismic UI on the web. I assigned the slices to the page type and then pushed the changes to Prismic to confirm everything matched before deploying our FE to production.
At this point all the page data seemed to be deleted from every page in the cms. Our production FE started returned a blank screen and our admin UI displayed no data. See image below. Previously this page had about 10 slices below the slice selector panel.
After trying to figure out what had happened I found the "Open your API endpoint in the web browser to test it in the API browser" link in settings/api & security
On this page we can see that all our data still exists if we use the html response only or if we switch the version in the url from v2 to v1. In which case v1 returns data in the json response for our slices. V2 returns only an empty slices array in the response.
See the image below showing the two versions responses side by side for the same page:
We have contact support multiple times and only received one very basic response 10 hours later, asking us to ensure that our slices are assigned to the custom page type (the exact action that caused the issue)... which they are. No other information or help was provided and we are yet to get another response from them. Our site has now been down for over 24 hours.
Prismic lacks any basic data inport/export functionality or data backup/recovery functionality. Im hoping someone in the community will be able to help. In the meantime we have manually been rebuilding our pages.
The migration documentation seems as if it was written by different people who did not collaborate so information is missing or the author expects detailed knowledge from the reader. It was not a straight forward upgrade.