The purpose of this article is to guide the customer on WHY they get this issue and HOW to resolve it:
Why does this error come up?:
This error comes up because the Supplier or Customer has not synced over to Xero. Therefore, this invoice cannot sync over either.
1) Go to the top right hand corner of Workshop Software and press the Xero sync button
2) Enter your email address and press "Ok".
3) This manual sync should take an hour to complete.