Are there any problem with server? After I key in all necessary and continue, it shows this "The connection was not closed. The connection's current state is open.An Exception has occurred.(ISR) "....
Are you attempting to purchase a renewal via ESET LLC (ie. www.eset.com) or your local disstributor or reseller? Each distributor handles purchasing licenses themselves. I'm not aware of any recent issues when speaking about ESET HQ or ESET LLC.
I bought it via local distributor. You can try by this link http://www.eset.sg/purchase/register/ there you try to key in your renewal serial no and the rest of your info and click submit. You will see the problem. I contacted local distri, they told me eset server side got some issue. You can try with one of the license key you have and you will see the issue.
This is a local distributor's issue and we have no clue why the error is returned as the website is maintained by the distributor. I've asked a colleague of mine to have somebody from the Singaporean team check out this thread. If necessary, I can generate a one-month trial license for you so that you are protected until the issue is sorted.