If you get the checkout error after the migration of data from Magento1 to Magento2, then make these tables in the database of Magento 2 according to number of stores. Like for one store one table, for two stores two tables and so on.
sales_sequence_profile.sql
sales_sequence_profile.sql
sales_sequence_meta.sql
sequence_invoice_2.sq
sequence_order_2.sql
sequence_creditmemo_2.sql
