This error means that the tax rate you have linked in Cloud Depot has been deleted in Xero
Compare your mapped tax rates in Cloud Depot to the tax rates in Xero.
1. Navigate in Cloud Depot to
My Accounting Toolbox - > Configuration -> Tax Mappings
2. On a new tab browser, in Xero, navigate to
Accounting -> Advanced -> Tax Rates
If you have a tax mapping in Cloud Depot that doesn't exist in Xero, remove it from your Cloud Depot (step 1 image) mapping using the delete button.
If you have created a new tax rate in Xero make sure that you map that new tax rate in Cloud Depot.
Please note your tax rates will be cached in your session, if you have recently created a tax rate in Xero, log out of Cloud Depot then log back in to refresh the cached data.