Client sold rental property in 2019.  While reviewing the original purchase closing statement to enter  the disposition information and adjustment to cost basis, realized the original cost basis entered by prior tax preparer is incorrect.  So...when I enter the correct cost basis, this results in a negative AMT Adjustment Preference, which I believe is why I get the following diagnostic error...."Please review AMT NOL entry for dispositions.  It appears to be greater than the amount used to figure AMT".  If the basis has been corrected, isn't this adjustment okay to leave as is, or do I need to make adjustments elsewhere?  

Hoping someone can assist me.