Hello everyone,

When trying to cancel Draft invoices, an exception is thrown. The error in the logs is 

ERROR:  duplicate key value violates unique constraint "account_invoice_number_uniq"
DETAIL:  Key (number, company_id, journal_id, type)=(, 1, 2, out_invoice) already exists.
Query failed
PostgreSQL said: duplicate key value violates unique constraint "account_invoice_number_uniq"
Detail: Key (number, company_id, journal_id, type)=(, 1, 2, out_invoice) already exists.

According to postgresql, the query it is trying to run is 

UPDATE "account_invoice" SET "internal_number"='',"number"='',"write_uid"=5,"write_date"=(now() at time zone 'UTC') WHERE id IN (1873)

It looks like the value for number is not being passed.

Any suggestions ?