Cannot upgrade to v12 due to sql_identifier data type
You need to find the columns with that type outside of information_schema.  Information_schema is not user tables, they are system tables.
SELECT * 
FROM pg_attribute 
  join pg_class on attrelid=oid 
  join pg_namespace on relnamespace=pg_namespace.oid 
WHERE atttypid::regtype::text like '%sql_identifier' 
  and nspname!='information_schema'