Since zbrush4r8 i have the problem that sometimes mehes that were generated i think by zRemesher, dynaMesh or extract stop being “meshes” where all the mesh functions like mirrorAndWeld… would be greyed out, and i need to hit the makePolymesh3d button to make it work as a mesh again.
All of us artists here have that problem.
Did anyone had the same issues and found a solution for that ?
thanks 
I have version 4R8 P2 on a PC, and I don’t have that problem.
It is not always happening, i don’t know the exact cause.
It is only speculation on my side that it has to do with those functions.
But the others ment they were pretty sure they have used one of those features when they ran into the problem.
It happened for me a few times, too.
But i couldn’t say for sure since i didn’t notice the problem right away.
Only after working a while with the mesh but then i needed to do something line “mirror and weld” but that didn’t work anymore until i hit the “make polymesh3d” button.
but thanks for checking.