Tiling featuer not appearing

Tiling does not appear as a cut option in material setup - with a 15.5" Y spoil board - and 5.5" X 36" Y work piece.
using a Genmitsu 4040 w/ 1/4" flat spral bit and 300W spindle.
Begins ok, but fails with STL import!

what must I be doing wrong?

Are you using Easel Pro? You need Pro in order to do tiling.

When setting your material size, there is a toggle button in the lower left to “Enable Tiling” and you have to turn it on.