MKL inspector-executor mkl_sparse_optimize returns SPARSE_STATUS_NOT_SUPPORTED

I'm trying to get a test program working with the MKL inspector-executor framework, but I'm getting the rather opaque error code SPARSE_STATUS_NOT_SUPPORTED from mkl_sparse_optimize and it isn't clear what I'm doing wrong. I was hoping I could get some help. Below is a snippet of my code:

71             sparse_matrix_t mkl_ie_csr;
72             CHECK_IE(mkl_sparse_d_create_csr(&mkl_ie_csr,
73                     SPARSE_INDEX_BASE_ZERO, mkl_csr.m, mkl_csr.n,
74                     mkl_csr.row_pointers, rows_end, mkl_csr.columns,
75                     mkl_csr.values));
76
77             struct matrix_descr descr;
78             descr.type = SPARSE_MATRIX_TYPE_GENERAL;
79             descr.mode = SPARSE_FILL_MODE_LOWER;
80             descr.diag = SPARSE_DIAG_NON_UNIT;
81             // May return 6 (SPARSE_STATUS_NOT_SUPPORTED) if repeats == 1
82             CHECK_IE(mkl_sparse_set_mv_hint(mkl_ie_csr,
83                     SPARSE_OPERATION_NON_TRANSPOSE, descr,
84                     repeats));
85             CHECK_IE(mkl_sparse_set_memory_hint(mkl_ie_csr,
86                         SPARSE_MEMORY_AGGRESSIVE));
87             CHECK_IE(mkl_sparse_optimize(mkl_ie_csr));
88             for (r = 0; r < repeats; r++) {
89                status = mkl_sparse_d_mv(SPARSE_OPERATION_NON_TRANSPOSE, 1.0,
90                        &mkl_ie_csr, SPARSE_MATRIX_TYPE_DIAGONAL, x, 1.0, y);
91                assert(status == SPARSE_STATUS_SUCCESS);
92             }

CHECK_IE is just a macro that verifies SPARSE_STATUS_SUCCESS, and exits otherwise.

When I run this example, I get the error on line 87 after calling mkl_sparse_optimize. Now, if I remove the call to mkl_sparse_optimize everything runs and validates against my reference data so it seems like this is mostly correct. I just don't have any understanding of what specific misconfigurations could be causing an unsupported error to be returned from mkl_sparse_optimize. Can I get any clarification on that?

Thanks!

Max