Slices aren’t displaying in the Editor.
Refresh browser, clear cached re-login to appsheet.
If they dont solve, I suggest to report to firstname.lastname@example.org for help
I had that happen to me yesterday for the first time. I closed my Chrome tab and reloaded AppSheet and it worked. I didn’t have to delete the cache.
This happened to me last night when I deleted a table before deleting a slice that used that table. To fix, I reloaded the app editor, re-added the table temporarily, deleted the slice, then re-deleted the table.
This is a known problem and should be fixed “soon”.
I believe same is valid for UX views as well @Steve