本人是mplus软件初学者，在进行模型拟合，并想要计算特质分数，但是警告提示协方差矩阵非正定（完整警告内容如下），请问应该如何理解呢？又该如何调整数据或者模型呢？谢谢！

    WARNING:  THE RESIDUAL COVARIANCE MATRIX (THETA) IS NOT POSITIVE DEFINITE.
     THIS COULD INDICATE A NEGATIVE VARIANCE/RESIDUAL VARIANCE FOR AN OBSERVED
     VARIABLE, A CORRELATION GREATER OR EQUAL TO ONE BETWEEN TWO OBSERVED
     VARIABLES, OR A LINEAR DEPENDENCY AMONG MORE THAN TWO OBSERVED VARIABLES.
     CHECK THE RESULTS SECTION FOR MORE INFORMATION.
     PROBLEM INVOLVING VARIABLE I2I3.

     WARNING:  THE LATENT VARIABLE COVARIANCE MATRIX (PSI) IS NOT POSITIVE
     DEFINITE.  THIS COULD INDICATE A NEGATIVE VARIANCE/RESIDUAL VARIANCE FOR A
     LATENT VARIABLE, A CORRELATION GREATER OR EQUAL TO ONE BETWEEN TWO LATENT
     VARIABLES, OR A LINEAR DEPENDENCY AMONG MORE THAN TWO LATENT VARIABLES.
     CHECK THE TECH4 OUTPUT FOR MORE INFORMATION.
     PROBLEM INVOLVING VARIABLE TRAIT2.

     THE MODEL CONTAINS A NON-ZERO CORRELATION BETWEEN DEPENDENT VARIABLES.
     SUCH CORRELATIONS ARE IGNORED IN THE COMPUTATION OF THE FACTOR SCORES.
     THE MODEL COVARIANCE MATRIX IS NOT POSITIVE DEFINITE.
     FACTOR SCORES WILL NOT BE COMPUTED. CHECK YOUR MODEL.