我也遇到这样的问题，不知道原因。哪位好心人解答下

If you are using Version 3.13 it should point to which variable has the problem. You may have a negative residual variance or a correlation of one somewhere. You can see the negative residual variance in the results and you can ask for TECH4 to see if any variables have a correlation greater than one. Otherwise, you may have a dependency among two or more of your variables. If it is a small negative residual variance, you could fix it to zero. Otherwise, you would need to change your model. If you can't figure this out with this information, please send your input, data, output, and license number to support@statmodel.com.
刚搜到的

and what can we do ?

我做的模型很多，选择另外的模型了。

哦。。 我是复制一篇论文的模型 出现那个warning 不知道作者是怎么弄出来的。。。