MID Server shows “AMB client disconnected after connecting” after upgrade to Australia

deebika019
Tera Contributor

4 hours ago

After upgrading our ServiceNow instance to the Australia release, we are observing an issue with the MID Server.

  • MID Server is Up and Validated
  • Latest MID version (Australia) is installed
  • MID is refreshing normally (Last refreshed: May 27, 2026)

However, under MID Server Issues, the following error is still displayed:

AMB client disconnected after connecting

 

observations:

  • The error was last detected on May 23, 2026
  • No additional occurrences observed after that
  • Restarted the MID Server, but the issue record is still visible
  • Threads and AMB client processes appear to be running normally
  • MID is deployed in a customer network environment (behind firewall/proxy)

 

Actions Taken:

  • Restarted MID Server service
  • Verified MID Server version compatibility
  • Checked MID status and refresh (working fine)
  • Reviewed threads → AMB-related threads present
  • Verified that issue is not continuously increasing

Additional Question:

If this needs to be fixed, what further troubleshooting steps should be performed beyond:

  • Checking agent logs
  • Validating WebSocket / proxy configuration
  • Reviewing SSL/certificate setup
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1 REPLY 1

Tanushree Maiti
Giga Patron

59m ago

Hi @deebika019 

 

Refer KB: KB2960053 AMB Client Disconnect Errors on MID Servers and Action Plan 

 

Resolution

Steps to Resolve
1. If the AMB disconnect occurs during/after patching and the count stays at 1 and does not increment after the next scheduled job cycle, treat it as transient. Mark the error as resolved and monitor for recurrence.
2. If the count increments across multiple scheduled job runs (e.g., reaches 2, 3+), treat it as persistent. Investigate root causes (network, proxy, WebSocket, SSL) and restart the MID Server to confirm the resolution.
3. If the MID Server status shows "Down" in addition to the AMB error, restart the MID Server regardless of the count.

 

Also check: https://www.servicenow.com/community/itom-forum/amb-client-disconnected-after-connecting/m-p/2931536

 

 

Please mark this response as Helpful & Accept it as solution if it assisted you with your question.
Regards
Tanushree Maiti
ServiceNow Technical Architect
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