look if there are these messages
(1) The correlation matrix is not positive definite
So, You do not get the KMO measures or Bartlett test, but you do get the PC analysis. This implies that the correlation matrix is positive semidefinite but not positive definite (no negative eigenvalues, but at least one 0 eigenvalue). In this case, the determinant of the matrix is 0, which means that the matrix is singular (cannot be inverted using a standard inverse).
The KMO measures require inversion of the matrix, so they cannot be printed. The Bartlett test statistic is a function of the log of the determinant, so it also cannot be computed, since the log of 0 is undefined. The PC analysis results are nevertheless valid, though you may want to identify the sources of the dependencies and reduce the variables
(2) or you get two messages
>Warning # 11301
>The correlation matrix is not positive definite.
and
>Warning # 11283
>Non-positive eigenvalues have been found and the matrix is not positive
>definite. This may be due to pairwise deletion of missing values.
You get no KMO measures, no Bartlett test and no PC analysis results. This means that there are negative eigenvalues. If your correlation matrix is computed in FACTOR from raw data without pairwise deletion, this would imply imprecision in our calculation of eigenvalues, since correlation matrices involving Pearson correlations and full data are by definition non-negative definite (have no negative eigenvalues)
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