Broadcast Error while powering down Steem Power

Hey guys,

first of all: a merry christmas to all of you.

I want to powering down my Steem Power. They ask me for my private password to do that.
So my first question is, where can i find that one? (I used to click at the "show private keys"-buttons in the wallet)

If i take one of these, i get a "broadcast error" and nothing happens. What can i do?
I need a simple answer, please.

Thank you!
Greetings