When TurboTax says your disallowable and allowable AMT gains and losses exceed your business basis, it means you're trying to claim more losses than what the IRS allows based on your investment in the business.
To fix this issue:
1. Double-check the numbers you entered for your business income, expenses, and basis (or investment). Make sure you didn't accidentally enter something incorrectly.
2. Review your business basis amount. Your basis is generally what you've invested in the business (money contributed, loans you've made to the business, etc).
3. If you're an S corporation shareholder or partner in a partnership, check if you received a K-1 form that shows your correct basis amount.