I do not know what the problem is, but it seams that i cant cross save anything. Please somenody help.
Cross-save does not apply to what you are trying to do. Cross-save is for utilizing a single set of save data over multiple platforms, between Xbox, PS4, and PC. You are looking for the Steam migration, to move your Battle.net data to Steam. This is done via the PC Move page, here on Bungie.net.
You cant cross save from battlenet to steam they are the same platform. Battle net goes away when steam goes live.