Slitherine

I'm trying to play CTGW against opponents but I'm having difficulties.
I am being asked for a password and, no matter what I enter, I get the message that my connection has timed out.
Am I doing something wrong?

If there is a lock symbol shown next to a challenge, then it's a private challenge. You can't join a private challenge unless you know the password which you would normally get from the user who opened the challenge. Usually such arrangements are being made in the "opponent finder" subforum.

Indeed there is.
I thought this was a personal challenge to me as it appeared on my list.

If you want to play multiplayer then you should start an "open" challenge and wait until someone accepts.

More puzzlement!
I signed on to Slitherine and saw I had a message.
The message said that I have a challenge in CTGW - nothing else: No opponent, no password, nothing!
I then got into the game and found no challenges there!
What's going on?

Probably just a "hiccup" caused by the forum's software.