By default, correlation matrixes are checked for consistency whenever you click OK in the Define Correlations dialog. If a matrix is inconsistent, a warning is displayed. You can choose to have Crystal Ball adjust the correlations, you can ignore the inconsistency and continue saving the correlation as is, or you can cancel and return to the Define Correlations dialog for editing.
If a matrix becomes inconsistent after you create it, the next time it is opened, you can see how it changed and edit it further.
To disable automatic consistency checking, open the Define Correlations dialog for a matrix and select Matrix, and then Check Matrix Consistency.