My repository is setup for an older Gatsby project. Currently we don't have any possibility to update to NextJS or Nuxt. We need now to add one of the existing slices and to add an additional field.
Recently prismic changes something so that editing existing slices (created using the legacy editor) is not possible anymore. Neither creating new slices is possible anymore.
Please give me a solution as I am currently blocked.
It seems as though you are painted into a corner. You have constraints on both sides of this equation. I haven't been able to find any announcements about the legacy type builder and being unable to change slices. Of course, while I was searching, I came across this post by Angelo.
As someone who's moved at least 3 sites from Gatsby to Next and Prismic, I can tell you that it sure is work, but it was absolutely worth it in the end.