Well, like others in this post, I finally was able to connect. I don't know what worked -- entering wrong login information, restarting TT, trying at odd times of day, sheer repetition, or what -- but I finally was able to download my info.
I suspect (and this is only a guess), that it's a capacity issue on the Schwab's side.
But TT could have been more helpful. The vague error message could have been clearer (what went wrong?), the suggestion to contact customer service could have been more specific (TT? Schwab?), and they could have provided a phone number.
