Someone else on the forum has said that they bought a 2TB B2 from Amazon UK but Amazon seems to have shipped them a 240GB unit instead of what they ordered. Are you absolutely sure that you have received a unit with a 2TB drive, and not a 240GB drive by mistake? That's the first step in answering your question.
If your B2 really contains a 2TB drive, the next thing is to looks at where the import actually stops. The B2 doesn't cope well with long file names (over about 170 characters), or some "special" characters. Do you have any idea what the "next" file would be?, i.e., the one it stops at and refuses to go further.
Maybe we can get some more info here.