Hello,
You can read in LECDON_TELEMAC3D that element 51 is prisms cut in tetrahedra (find IELM3), which seems to say that you have chosen ELEMENT = TETRAHEDRON.
You can also find in MURD3D_LIPS subroutine your error message, read the comment just above: "SCHEME IS IMPLEMENTED ONLY FOR PRISMS AT THE MOMENT".
The error message tells you that LIPS advection scheme is not implemented for prisms cut in tetrahedra.
If you change default choices, you should think why you do it.
Hope this helps,
Chi-Tuan