When the sampling throws that error, it usually prints the test point. If not, you can print model.check_test_point(). If I had to guess, I would suspect that M and thus mu and thus n is too small relative to your data.
When the sampling throws that error, it usually prints the test point. If not, you can print model.check_test_point(). If I had to guess, I would suspect that M and thus mu and thus n is too small relative to your data.