Thanks for reporting these to me! and thanks for buying my plugin!
Regarding the errors:
1: [It can't save the mesh file until you create SavedMeshData folder (not in the package).]
-I added a check and a fix for the folder thing (Thanks for catching that!)
2: [the collider data does not save as a usable mesh]
-Although not intended in the initial release, this is a good idea and I've added your "m.hideFlags = HideFlags.None;" fix. Thanks! Now you can use the created mesh as regular meshes!