Troubleshooting KRC connection failure


  • Kaseya Remote Control (KRC) sessions persistently fail to connect

  • KRC sessions are persistently dropped

  • KRC viewer reports “connected” but remote desktop is not displayed



There is no universal cause, but common issues include: -

  • a firewall blocks websocket connections between viewer machine and kserver, or between agent machine and kserver

  • a content filtering service on a firewall blocks packets it does not recognise

  • in some earlier builds of VSA R7, viewer would attempt connection over incorrect port



To isolate the source of problem, perform these basic troubleshooting steps: -


1) test connection to several different agents on different remote networks, in case the problem is related to a specific agent or network location

2) test connection from a different network location

on-premises customers only: -

3) test connecting to the kserver agent

4) log onto the kserver console (using another remote desktop tool such as RDP), log onto Kaseya using http(s)://localhost, and from there try to connect to external agents using KRC

5)ensure VSA server has the latest patches and uninstall Kaseya Remote Control from “viewer” machine (latest build of the viewer will be installed on new connection


Depending on the results of the above tests, check the firewall logs and configurations in the affected locations (viewer, agent, or kserver) for the following: -

  • are any packets dropped: -

- between viewer and kserver on the same port that you access the VSA web interface with (usually 80 or 443)

- between agent and kserver on the agent check-in port (usually 5721)

- between agent or viewer and on port 3478 (TCP or UDP)

  • is there any content level filtering enabled? If so, temporarily disable it and re-test KRC.
  • is HTTPS inspection or similar service enabled on firewall? If so, click here for further details



If further assistance is needed, please provide Kaseya Support with the following information: -

1) exact description of problem condition, with screenshot of any on-screen error message or unexpected behavior

2) details of steps mentioned above, and any other troubleshooting steps taken so far

3) KRC logs from viewer and agent machines, captured just after reproducing the problem


Agent Logs

  • Windows XP and 2003: C:\Documents and Settings\All Users\Application Data\Kaseya\Log

  • Windows Vista and later: C:\ProgramData\Kaseya\Log

  • OS X: /Library/Logs/com.kaseya


Viewer Logs

  • Windows XP and 2003: C:\Documents and Settings\<user>\Application Data\Kaseya\Log

  • Windows Vista and later: C:\Users\<user>\AppData\Local\Kaseya\Log

  • OS X: /Users/<user>/Library/Logs/com.kaseya



Kaseya VSA R7 and above

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