AP transaction posted without invoice number

[ehuelsmann]

Version

1.11.14

What browsers are you seeing the problem on?

This problem isn't browser related

What happened?

Created an AP transaction, saved without invoice number. Then went on to post the transaction.

The result is an AP transaction without an invoice number.

What should have happened?

Although it's dubious that an AP transaction can be saved without an invoice/reference number, it should absolutely be impossible to post the transaction without an invoice number.