[Answered ]-Errors when viewing pages with children in admin UI after DB migration

I had the same problem. I think when I moved the data from sqlite3 to postgresql the wagtailcore_page column translation_key got changed to column type ‘integer’ from ‘uuid’. The problem is solved by changing translation_key to ‘uuid’ by using the following Postgres command:

ALTER TABLE "wagtailcore_page" ALTER COLUMN "translation_key" SET DATA TYPE UUID USING "translation_key"::UUID;