We've recently been made aware of a problem that would prevent CorelDRAW Graphics Suite X6 (the original version) users from upgrading to X6.1 (the first update / service pack). The root cause for this issue has been identified and we will be fixing the problem with an upcoming update on our servers scheduled for June 11th, 2015. In the meantime, if you need to update X6 to X6.1, please contact our technical support team who can help with a workaround solution.
I've checked with the team, and they have experienced some problems pushing the fix to production. I've been told it should go live sometime Monday June 15. I will try to post an update as soon I as get confirmation the fix is live and working properly.