It is a common issue that some of the download mirrors may be down or be hit by traffic, this method suggests a way to continue downloading the file that you had paused from a alternate mirror (or) url. I use Internet Download Manager and it’s one of the best in the business. To continue your paused download from a different mirror , just get the address to your alternate mirror from the from the source , (AFAIK most of the websites these days provide links for alternate mirrors especially for downloading massive files). Go to IDM , right click the file that was paused, click on Properties and change the address to the address of the new mirror url, now you can resume your download at a higher speed. Choose the mirror that is relatively close to you for better speeds.
HTH