Gmod server not downloading files

I have purchased a gmod 13 server and when I read the logs I see that addons from my collection in workshop start downloading and some of the bigger addons fail at 50%.
How is this fixable?
Thank you in advance :smiley:

[editline]26th September 2013[/editline]

Hmmm, found a temp. fix. You download addons on beta gmod and transfer them on my usual server