ok so here is what i realised.
i crash the same on cubase and nuendo after a while.
if i remove the %appdata%/Steinberg folders then it works fine again for a while…
maybe it’s because i save a pref that is a problem but it’s the same on cubase and nuendo.
i also think it happen after a crash on exit. i get an error message (a serious problem has occured…) and then when i try to reload the session after reboot it’s impossible. i crash all time just after loading is done.
the only thing to do is delete the %appdata%/Steinberg again.