Error when creating an order from a draft order

[raphaellimagb]

I'm facing this error on the image below:

Could someone explain why I'm receiving this error?

[DaisyVo]

Hi @raphaellimagb 

Could you please re-check the order to see if it has changed?

Best,

Daisy

[raphaellimagb]

The error was resolved, but I need to know what caused it. I tried to replicate it, but haven't been successful so far.