When generating prism mesh, preparation is essential. It is easier to edit a tetra mesh than a tetra/prism mesh. A prism mesh can also be difficult to smooth, so it will save time to start with good quality tetra or tri-surface mesh.
Start with a Tetra-volume mesh or Tri-surface mesh.
Check aspect ratios and quality.
Highly skewed or low quality elements are not suitable for prism growth.
Check and fix all diagnostics.
Single/multiple edges, non-manifold vertices, and duplicate elements will crash the prism mesher.
Visually scan the surface mesh.
Look for and repair any surface discrepancies or sharp tent-like structures in the mesh.
Make sure part associations are correct.
Look for a few elements of one part scattered among another part. Extruding from a few isolated elements will likely crash the prism mesher. Modify part assignments of such elements.
Use the Smoothing Options for Tetra and Tri surface mesh under > > when creating the prism mesh.
Laplace is typically the best option for Triangle Quality type for the eventual prism quality.