If your having some error like miscellaneous error occurred when open treasure NPC, achievement board, hard/easy summon NPC, killing race , BDW and others NPC similar kind. You can follow the steps with the image that is posted below.
Steps:
Step 1: Right click on the Network Icon from your taskbar from the right bottom and click on Network and Sharing Center.
Step 2: Click on Change adapter settings.
Step 3: Click on the icon Local Area Connection and then Right Click on Properties. Press Ok.
Step 4: From the Local Area Connection Properties tab, unchecked the Internet Protocol Version 6 (TCP/IPv6).
I hope this will help. Thank you