SONAL10,
The first question you want to answer when troubleshooting that error is "How long does it take for that error to appear after clicking the 'Connect' button?"
If the answer is more than just a few seconds then this is typically a connection error.
You can confirm that it is a connection issue by running a trace route to 204.8.240.1
For details on how to run a trace route refer to this thread:
Complete Error Message List
If you see *s or "request timeout" messages that is likely the reason it is having trouble. That's indicating data is getting lost along the way as traffic flows across the internet. Also you typically want to see the milliseconds be no higher than 250ms.
If you do determine that it is an internet connection problem there are some public proxy servers that work a lot of times.
What you'd do is open the software, cancel out of the login prompt. Click System, Proxy Settings, click 'Next' twice, place a check mark where it says "Use proxy server", type in the host and the port I will give below, then click 'Next', then click 'Finish.'
Here are a few hosts and ports that generally work a decent amount of the time in the Asia region.
Host: 165.228.129.10
Port: 3128
Host: 208.83.221.138
Port: 3128
Host: 202.83.197.168
Port: 3128
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If one of these works it means it was successful in routing the data through an alternate path across the internet.
This means there is a problem with your internet connection and it would still be a good idea to contact your internet service provider for a possible solution.
And of course if none of the proxies work the only course of action is to contact the internet service provider and have them take a look at their network. You can use the trace route as proof if they want details.