Applications Systems

Form Login Monitor Not Working

Receiving an error with the SAM Form Login Monitor. Execution method for htmlClients has failed. Object reference not set to an instance of an object

First published date

10/22/2019 4:15 PM

Last published date

3/9/2022 1:34 PM

Overview

Form login component monitor within SAM may fail without proper TLS settings enabled. Below is an example log entry of the failure of the form login monitor. You must first turn on application debugging to view this error.

ERROR SolarWinds.APM.Probes.ProbeBase`1 - Unhandled exception.
System.AggregateException: Execution method for htmlClients has failed. ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at SolarWinds.APM.Probes.HTML.HTMLClient.GetElements(String xpath, String valueAttr, Boolean nameRequired)
   at SolarWinds.APM.Probes.HTML.HTMLClient.GetForms()
   at SolarWinds.APM.Probes.HTML.AggregatedFallbackDecoratorHtmlClient.<>c.<GetForms>b__5_0(IHTMLClient x)
   at SolarWinds.APM.Probes.HTML.AggregatedFallbackDecoratorHtmlClient.ExecuteWithFallbackOnError[T](Func`2 func)
   --- End of inner exception stack trace ---

Product section

Server Application Monitor

Cause

TLS 1.2 is disabled on the SolarWinds Platform polling engine.

Resolution

Enable TLS 1.2

  1. RDP to the SolarWinds Platform polling engine.
  2. Go to Start > Run > Regedit
  3. Navigate to KEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2
  4. Verify that both Client and server folder entries exist.
  5. Within each server and client entries, find or create REG_DWORD values: 
  • DisabledByDefault with the value set to 0 decimal
  • Enabled with the value set to 1 decimal
  1. Reboot the server.