hello!
I painted the mask, I click on the tool “masking------> make alpha”
this is the alpha…why?? Is it possible to fix it?
On the same computer, zbrush 4 work fine, I tried to reinstall the 4R2 but this problem still…HELP
this is a bug in Z4R2… unfortunately pixologic doesn’t release patches to fix bugs, so you’ll have to wait until the next release for it to be fixed… apparently they don’t do regression testing either, because every version that comes out results in one or more previously working features breaking 
I’ll be waiting for the next update! thanks for the answer!!
This is indeed a bug in R2, and affects any function that derives a texture or alpha directly from masking, but you can work around it by inverting the mask, and filling that object (Color>Fill Object) with dark color. You can then convert that polypaint to Texture(Texture Map> Texture from Polypaint).
You can use that texture to apply masking (Mask by intensity), or convert it into an alpha.
As to what Pixologic is, or isn’t going to do, no one here has any idea. For what it’s worth, they’ve made statements on the board that have suggested to me that they were working on an update that wasn’t the next official release (ZB5). Take that for what it’s worth, as in completely unofficial speculation.