When you are looking at that dialog with the disabled Finish button, there is a big textbox with a lot of messages in it.
If you click in that textbox you can select all of the text by pressing "Ctrl + A" and then copy the text to the clipboard by pressing "Ctrl + C".

Can you send us all of the text from that textbox? There might be a useful message hidden somewhere within all of the text which will give us some hint as to what went wrong.
-- Nick