Last update problem

[Stuka]

If I have installed all the 476th modes (all 3 Required Mods + 476th_Skins_v2.3) then is OK for 476th DS.
But the all other free servers from the DCS servers list are no longer available for me
Now is no longer possible to fly KA-50, FC3 or P-51 on the other servers
Is this normal?

Yes always have been.
That "other server" might have all the previous mods we had, but not the updated mods That's why it worked before.
Nothing you can do about that, unless you start sharing internal mods, and you know we don't allow that.

Besides that, it's perfect possible to run multiple installations of DCS. Some of us do it all the time.