How to confirm Despatch if the following error ‘Exception while generating transaction id,please try after sometime’ occurs on confirm?

Cause: System shows the error ‘Exception while generating transaction id, please try after sometime’ while confirming the despatch, When despatch is from site code A1 to site code B1 and on despatch confirmation system check the IBCA RCP control Link of customers for invoice and IBCA control link is not defined for these sites. This may happen, when users create new customers using a copy transaction then site code RCP comes automatically and it can be saved.
Remedies:
Users have to check and remove the site code receivables in Customer Master and Site Customer which is wrongly saved. Users need to ensure the correct values if the user creates the customer using a copy transaction. Then users can confirm the despatch.