When I click Edit then Save on some sales orders, there is an error "Subgroups not allowed"

AI generated answer (using internal Slack threads):

Based on the conversations, the error "You cannot edit the end of group line. You must delete the group" when trying to save an Invoice from the Next Bill button on Sales Order page is usually caused by a script or workflow running on the invoice record. If you have any scripts or workflows running on the Invoice items sublist, you might want to check them. The issue might be a workflow that is trying to update the end of group line. You can put a condition to only update items in the sublist that are not description items or do not contain “End of Group”. You can also try turning off all the scripts then turning them back on one by one to test which one is causing the error. As for the error "YOU_CAN_NOT_CHANGE_THE_CUSTOMER_OR_TERM_OR_BILLADDRESS_ON_AN_INVOICE_FOR_GROUPING", it might be due to the fact that modifying the shipping address is interpreted as changing the customer on the sales order. If invoice group is disabled on the sales order, the transformation might be successful. ****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ******