MuPAD : linalg::pseudoInverse(Matrix)

Someone is it able to help me with a pseudo inversion with MuPAD.
When I try to "pseudo inverse" this matrix :
     +-                                                          -+
      |   0,  1,  0,  0, 0,  0,   0,   0,  0, 0, a2, a3, a4, 0, 0  |
      |                                                            |
      |   0,  0,  0,  0, 0,  0,   -1,  0,  0, 0, a5, a6, a7, 0, 0  |
      |                                                            |
      |  a8, a9, a10, 0, 0, a11, a12, a13, 0, 0,  0,  0,  0, 0, 0  |
      +-                                                          -+

I get the following error :
Error: Illegal argument [_seqgen];
during evaluation of Dom::Matrix(Dom::ExpressionField()))::stackMatrix'

I don't understand. Thanks in advance for your help.

ArnO
.