I am unable to add any new slices to any existing or new documents. When I click on the slice I want to add, there is a console error. However, when I save the document, leave and return, the slice appears as normal.
The workaround of leaving the document, and returning again, is a pain for our content creators. This issue only began recently, and there have been no recent changes to the underlying custom types. All custom types were created using the Prismic UI, and not Slice Machine.
Is this expected behavior? Is there something missing from our custom type, or Prismic configuration that is causing this?
I'm having this exact same problem, since yesterday. I am unable to add slices to new or existing documents, with the same type of console error: Uncaught TypeError: Cannot read properties of undefined (reading '0').
I hadn't actually realized that if I saved the document, left, and came back that my new slice would be there, but I've tested that and it works for me as well.