Download Assistant Aria2 Resume ????

If the power goes out during a download how do you resume it ?
If you start it again it will give an error.
it’s taken 4 days to get to 90% so I don’t want to start again.

I tried the command line with aria2c.exe

aria2c -c
Exception caught
Exception: [] errorCode=1 Unrecognized URI or unsupported

I think I need the original download link, this link just has the old stuff that stops at version 6

As nobody gave a solution I thought I would solve the issue by just buying it on eBay, so I paid Express Post charges and it came the next day but it is just an empty box !
Is there any purpose at all in selling empty boxes exactly the same size as DVDs ?