Can not purchase item from marketplace, sale will soon end :(

Want to purchase the Luo’s Modular Rocks&Caves pack, but I get errors:
In launcher: Purchase failed! Error Code E60-0

In web Marketplace: Error 500


P.S.: in the error page of the marketplace there are social network icons at the bottom for facebook, twitter, g+. etc. but they are not linked. they all point to

After many many many tries I could purchase it now. Something’s really broken right now.
This issue can be closed!