Error
Unable to proceed, there is an existing batch for this invoice. (Invoice Number: )
Applies to: Autotask PSA
How can this happen?
This error can occur when syncing an invoice that has already been batched from AutoTask and the web service date has been cleared manually.
Solution
If the invoice needs to be re-synced to the accounting package, the batch has to be deleted in Wise-Sync. From the sync page, click the dropdown under sync result then select Delete Batch
However, if the invoice has already been synced and there are no changes required to re-sync the invoice. then from the sync page, find the invoice, set the Sync Action to t "Set Web Service Date in AutoTask" then click on Start Sync.