Unable to instantiate class AutoProbeTransformer
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Unable to instantiate class AutoProbeTransformer


Article ID: 218787


Updated On:


CA Application Performance Management (APM / Wily / Introscope)



.NET agent upgrade from 9.5 to 10.7 and facing the issue that the AutoProbe extension stops working. 

After switching on DEBUG logging level, could find the following in the Introscope Agent logging file. 


[VERBOSE] [IntroscopeAgent.Agent] Successfully registered event noticer "Object Creation Noticer" in extension "Introscope LeakHunter".
[INFO] [IntroscopeAgent.Agent] Introscope AutoProbe Release (Build 996104)
[IntroscopeAgent.Agent] Configuration property (introscope.autoprobe.logging) set to default value of ""
[ERROR] [IntroscopeAgent.Agent] Unable to instantiate class com.wily.introscope.autoprobe.AutoProbeTransformer
[VERBOSE] [IntroscopeAgent.Agent] 

System.NullReferenceException: Object reference not set to an instance of an object.
   at com.wily.introscope.autoprobe.AutoProbeTransformer..ctor(IAgent agent)
[VERBOSE] [IntroscopeAgent.Agent] Registered classfile transformer "ChangeDetector Assembly Transformer" in extension "Wily ChangeDetector Agent"
[INFO] [IntroscopeAgent] Fully Qualified Agent Host Name (introscope.agent.display.hostName.as.fqdn) set to "False"






Release : 10.7.0

Component : APM Agents

Seen in Windows 2008 but not Windows 2019



The problem could be the environment variable "WEBSITE_INSTANCE_ID" not always set in all Azure setup.




The code was updated to add a check for null or blank value of this environment variable "WEBSITE_INSTANCE_ID" and handle the log path creation accordingly. 

This will be made available in 10.7 SP4