"then" means "at that time" or "during this period"

I① A great deal of attention is being paid today to the so-called digital divide--the division of the world into the info (information) rich and the info poor. ② And that divide does exist today. ③ My wife and I lectured about this looming danger twenty years ago.④What was less visible then,however,were the new,positive forces that work against the digital divide. ⑤ There are reasonsto be optimistic. Here is. Sorry Robin, I don't know why I can't send message to you, this app stop me, can't even reply your remarks😖

It needs more context. Is it speaking about something that happens in the past?