Some plugins create tables in MYSQL without primary keys which may break exporting and importing actions.

We can identify where exactly with this SQL script:

SELECT
t.TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES AS t
LEFT JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS k
ON (
t.TABLE_NAME = k.TABLE_NAME
AND k.CONSTRAINT_SCHEMA = t.TABLE_SCHEMA
AND k.constraint_name = 'PRIMARY'
)
WHERE
t.TABLE_SCHEMA NOT IN ('information_schema', 'performance_schema', 'mysql', 'sys')
AND t.TABLE_SCHEMA = 'database name' -- put database name here
AND k.constraint_name IS NULL;