All agents give out the error Kaseya Live Connect Error: "Connection Could Not Be Established" when attempting to Live Connect to them. When you log into the VSA from a different machine, you are able to Live Connect.
Check the Live Connect Logs found here.
Viewer (the computer that KLC session is initiated from)
Live Connect and Admin Endpoint Logs:
Windows 7 and later: C:\Users\[username]\AppData\Local\Kaseya\Log\KaseyaLiveConnect
If you find the error (LC.Default) Admin account not authorized, please follow the resolution provided in the below section to clear the KLC cache.
1. Uninstall Live Connect from the Control Panel -> Programs and Features (appwiz.cpl)
2. Remove the folder - %localappdata%\Kaseya
3. Remove any files from C:\ProgramData\Package Cache
4. Reboot your machine
5. Open your VSA, initiate Live Connect, and follow the prompts to install and test Live Connect functionality