We were just discussing this above. Mega has a bandwidth limit. Once you reach it you have to wait up to 3.5 hrs to resume downloading. If you want to see exactly how much time you have left, right click on one of the downloads in your list that has “errored out” and select “open link in web browser” or something to that effect. There it will show a manual download button. Click on that and it’ll show a timer for how long you have to wait. It’s a pain. But that’s the cost of free downloads at Mega. It took me a week and a half to acquire all the files because of this.