Remember that only those errors should be disputed which have a valid reason behind them. If you want negative but accurate information removed from your credit report, you will need to negotiate with your creditors for the same.
Minor errors like a misspelled former employer or an outdated phone number — don’t affect anyone’s assessment of creditworthiness and aren’t worth disputing.
The Negative Flag might surprise you but that does not mean it is an error, if it is accurate so instead of disputing that try to resolve it directly to the creditors. For example, if you accidentally missed a payment, contact the creditor, arrange to pay up and ask if it will rescind the delinquency, so it no longer appears on your reports.