Sage 50 Accounts

I am importing invoices using the template and I keep getting the error: The tax goods analysis total does not match transaction net value. What causes this issue?

We have 777 Sales Ledger Accounts that haven't been used since March 2018 They have a balance of £111k which coincidentally is balanced exactly by a balance of £(111k) in a "Debtors" nominal account. I would like to clear down these accounts and start…