I noticed this when trying to apply some skin MATs.  The first one is Lindy Montana for V4 and another that shows the problem is Nanami for V4.  When the skin texture is applied via the MAT pose, there are cracks in the skin texture above the knees, at the shins, and shoulders.

Is this a result of poor skin textures?  Since it's happening with multiple skin textures that doesn't seem likely.  Photo is linked (BEWARE NUDITY.)

This happens if the MAT is applied to a zeroed figure, or to a posed figure, any time it's applied to V4 morphed or unmorphed.

Can anyone help by giving a reason and solution?