Domain was submitted for manual transfer. But now when trying to complete the order in Home > Operations > Provisioning error appears:
Can not mark Domain as transferred: Domain Status is Checking Transfer Status.
Domain status was changed manually in the properties of Provisioning Item of the Sales Order.
Order for domain manual transfer can be completed only when domain is in status Submitted for Manual Transfer.
In order to resolve the issue it is necessary to perfrom the following update in PBA-E database:
update "ADomain" set "Status" = 80 where "DomainID" = [if_of_the_domain];
Then it will be possible to complete the order.