GLM/manova- box's M problem


New Member
Hi, im running a MANOVA through GLM in spss. It seems to be having an issue with providing/running Box's M. spss gives this notice at the top of the output.

"Box's Test of Equality of Covariance Matrices is not computed because there are fewer than two nonsingular cell covariance matrices."

can anyone explain what this means and how i might go about solving this issue?

cheers :)