This is a common error message to encounter with SmartFees, and most frequently it seems to be caused by a mismatch between the loan property's Zip Code and County.
To fix this, go into the Loan & Property tab in the loan, and scroll down to the Property Info.
Make sure that the Zip Code and County are set correctly. In rare cases this error may still occur even with proper Zip and County, if most of the Zip Code is within a different County than the one entered here. If you've confirmed the Zip and County are correct but the error message persists, try changing the County to the one that covers the majority of that Zip Code and that should fix it.
If this doesn't fix the issue, please reach out to firstname.lastname@example.org