Applications Systems

Unexpected error occurred. TLS Security Exception accountable for fallback

SAM HTTPS component monitor was failing with "Unexpected error occurred. TLS Security Exception accountable for fallback"

First published date

2/14/2021 5:19 PM

Last published date

2/11/2025 12:52 AM

Overview

You have some HTTPS SAM component monitors that are working find and some failing with this error in GUI
Unexpected error occurred. TLS Security Exception accountable for fallback

And the component logs shows an error similar to: 
ERROR SolarWinds.APM.Probes.ProbeBase`1 - Unhandled exception.
SolarWinds.APM.Common.Utility.TlsFallbackException: TLS Security Exception accountable for fallback ---> System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a receive. ---> System.ComponentModel.Win32Exception: The client and server cannot communicate, because they do not possess a common algorithm

Server stack trace:
   at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)

Exception rethrown at [0]:
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at SolarWinds.APM.Common.Utility.WrapTlsFallbackException.Wrap[T](Func`1 action, IEnumerable`1 fallbackWebExceptionStatuses)


 

Product section

Server Application Monitor

Cause

  • Multi-factor authentication is turned on for the this node you have the component monitor on.
  • Other causes could be - The client and server cannot communicate, because they do not possess a common algorithm (supported Ciphers )

Resolution

  1. Ensure the website URL does not automatically redirect to any 3rd-party MFA provider, which of course is not what you wanted to monitor.
  2. Turn off / Disable Follow Redirect if enabled by default even though now MFA redirect is in place.
  3. Ensure that both client and servers support the same algorithms and TLS versions: