In case of an error order item moves to Error status. Order item has 'orderItemStatusText' which contains user friendly error text and 'errorCode' that can help developer react to error properly.
Error code consist of 6 digits and built by next schema:
|x-----||Error type 1 - Error during execution 2 - Validation error 3 - Validation warning 4 - Validation info|
|-xx---||Partner code 11 - Shared 12 - SBB 13 - Nova 14 - Shopify 15 - Tomas 16 - E-Liberty|
|---x--||Service type 1-fullfiller2-prefullfiller3-internal shared service4-partner service5 - updater6 - order state machine7 - canceler|
|----xx||Error identifier.A unique number of an error. These two digits are not globally unique and the foregoing numbers must be considered too.|
A description and a message of a validation error can be found in the API response in the validation message