If you can, try to send the invoice back to Compello from the ERP system you use or from its integration. If that isn't possible, in Compello Process, click the Admin option and select Client setup clientReactivate transaction. Enter the archive number of the invoice you want to reactivate and click the search symbol. Mark the invoice that appears and then click Reactivate. You will then find the invoice, active in the worklists with status Partly Posted. You can now check the coding values, change things and in the end change the status to Fully POsted again to retry transfer to your ERP system.