Cannot run the Miner

Hello together,

I hope it is okay to post this here, I am very new to Steem. Maybe this thread will then help others.. I did set all up as described in https://steemit.com/miner-category/@clayop/steem-miner-setup-in-ubuntu-15

Everything worked except the last step - to start the miner.

I typed:

screen -dmS steemd steemd --miner=‚[„mxk11“,“[My private active key]"]' --witness=‚“mxk11“‘ --mining-threads=4

to the console. The only output was in a new line:

(here is the cursor to type sth. in)

Does anyone of you have an idea why this happen?

Best regards
mxk11