Recurring Invoice message This Invoice already exists in the file when adding

When more than one user is creating a new Recurring Invoice, an error can occur:

• This invoice already exists in the file.

• Error inserting General Billing Recurring Invoice. Status -268 ISAM -2601.

• Cannot insert duplicate key row in object 'dbo.gbrecurh' with unique index 'gbrecurg1'.

• General Billing

• Recurring Invoices

More the one user is adding Recurring Invoices at once.

Development is currently researching the issue. 

Recurring Invoices was initially designed for a single user to create records at a time. Current workaround is to remove the record that is erroring and Add the record again.