I have an error: Error game js5connect Unable to connect to update server

This is likely due to the fact that your firewall is blocking outbound traffic on the ports 443, 43594 and 43595. To sort this follow the below steps:

You will need to consult your user manual/ help topics for the specific settings needed by your security programs/firewall/router.

1. Please add exceptions for the following domains in your firewall:
2. *.runescape.com, .Runescape.com
3. In particular, ensure that the following ports are unrestricted for both Inbound and Outbound TCP traffic:443, 43594, 43595
4. To make it easier to check if this affecting you, there's a program called 'ShieldsUP' that you could use that will tell you if those ports are open or not.