Rebuild Subdivions

I applied the generate > rebuild subdivisions on the shrinkwraped model but it says ' NO VALID SUBDIVISIONS FOUND TO REBUILD THE LOWER LEVEL'  Is there any way to solve this ?
  • Kent Trammell replied

    That error means there must be some modification (even unintended) between applying the subdsuf modifier and rebuilding subdivisions.

    This could be anything that alters the polycount or vertex order: Cutting an edge or merging vertices for example.

    I recommend trying to steps one more time and make sure you're not modifying your mesh at all through it.