This error can happen with Invoice posting and/or supplier invoice posting occurs when:
- Not logged in with a user with sufficient enough posting permissions (Login as ADMIN user)
- Rounding is mapped with a non-conforming code (e.g. N-T when it should FRE)
- Default mappings are not setup for "General" or "Rounding" in Spearhead "Accounts > Sales Invoices"
- Login as Admin User (or user with Admin rights)
- Check tax codes setup correctly
- Check default mappings in Spearhead and AroFlo