Hello Petr,
Yes, you are right: this message is undocumented. We are aware about this gap in the documentation and will try to fix it soon. Anyway, having an error returned after DSS function (a numerical value), you can look at mkl_dss.h header file and find corresponding named constant respecting to this error. It will help you to understand meaning of the error:
#define MKL_DSS_SUCCESS 0
#define MKL_DSS_ZERO_PIVOT -1
#define MKL_DSS_OUT_OF_MEMORY -2
#define MKL_DSS_FAILURE -3
#define MKL_DSS_ROW_ERR -4
#define MKL_DSS_COL_ERR -5
#define MKL_DSS_TOO_FEW_VALUES -6
#define MKL_DSS_TOO_MANY_VALUES -7
#define MKL_DSS_NOT_SQUARE -8
#define MKL_DSS_STATE_ERR -9
#define MKL_DSS_INVALID_OPTION -10
#define MKL_DSS_OPTION_CONFLICT -11
#define MKL_DSS_MSG_LVL_ERR -12
#define MKL_DSS_TERM_LVL_ERR -13
#define MKL_DSS_STRUCTURE_ERR -14
#define MKL_DSS_REORDER_ERR -15
#define MKL_DSS_VALUES_ERR -16
#define MKL_DSS_STATISTICS_INVALID_MATRIX -17
#define MKL_DSS_STATISTICS_INVALID_STATE -18
#define MKL_DSS_STATISTICS_INVALID_STRING -19
#define MKL_DSS_REORDER1_ERR -20
#define MKL_DSS_PREORDER_ERR -21
#define MKL_DSS_DIAG_ERR -22
#define MKL_DSS_I32BIT_ERR -23
#define MKL_DSS_OOC_MEM_ERR -24
#define MKL_DSS_OOC_OC_ERR -25
#define MKL_DSS_OOC_RW_ERR -26
Regards,
Konstantin