Sort:  

If you wait the 4 weeks it takes to power down, then yes. I advice would be to hold them. steem might be worth some money one day.

How to open a ticket? Is there any help from the people who run this platform? I tried to power down but got this error message:

Did you remember your wallet password?

Sorry for the late reply voidsoul. Yes I managed to power down as you explained and now I can see my Steem. All I want is to send them in a platform I can sell them. How to proceed, choose "Transfer", "Market", "Trade" ? I'm not used to this platform, find it cumbersome and complicated.
I tried to reward your help, no success.
I try to move my STEEM, can't find out.
I manage 68 different coins on 19 different platforms and wallets. Steemit is definitively not for me unfortunately
so I try to escape but you are the only one that seems able to help.
Many thanks for the help so far, dealing with unsupported platforms gives me Kafkaian anxiety.
And yes I remember all my passwords and keys.

I tried to upload the screenshot of my error message. I'm asked to log in first (I'm already logged in!!!).

Coin Marketplace

STEEM 0.17
TRX 0.24
JST 0.033
BTC 95224.32
ETH 2655.43
SBD 0.43