why do i get this error when I change a approval status (field id: approvalstatus) from approved to pending approval Approved Invoice cannot be set to Pending Approval or Rejected status

AI generated answer (using internal Slack threads):

The error message "Approved Invoice cannot be set to Pending Approval or Rejected status" is a system limitation in NetSuite. Once an invoice has been approved, it cannot be reverted back to a 'Pending Approval' or 'Rejected' status. This is to maintain the integrity of the approval process and to prevent any potential issues with financial reporting or auditing. This limitation applies even if all scripts and workflows are turned off. It is also not affected by whether the invoice is in a locked period or not. As for a workaround, there isn't a direct one due to this being a system limitation. However, you could consider creating a custom field to track a secondary 'approval status'. This field could be updated by your workflows or scripts to reflect a 'Pending Approval' or 'Rejected' status, even if the system 'approval status' field cannot be changed. Please note that this workaround would not affect the system's recognition of the invoice's approval status, and would only serve as a visual indicator for your users. ****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ******