Bounce bank on Fiat bank transfer of French account

[Anastasia]

Hello, I have had two bounce bank on recent Fiat bank transfer from a french bank account. The cause given for the OASIS Refund: Contract ID missing/invalid (see attached).What does this mean? I have successfully made transfers before. Thank you.

[Faberto]

Make sure that every transfer you include the correct purpose. It changes for every transaction.