If you are having errors on the CLI then I recommend editing datadir/config.ini
The default generated on should provide a template.
Names starting with n, t, and f are being flagged by the JSON parser "null", "true", and "false".
If you don't use quotes then those names will fail.
All of this is backwards steemd will not run with any names that are started with a letter other than n, t, or f. Otherwise, it is needed to be started with a number. Why is it working the opposite of what you say?
You are doing it wrong. Don't use a number.
The dev's instructions are wrong.
Use this:
witness='"yourname"'
The json parser is looking for quotes, so you have to single-quote them in the shell. Make sure you single quote the miner array too, but don't single quote the seed node.
--miner='["yourname","5........."]'
--seed-node="52.38.66.234:2001"