New .NET Agent Install Causing TLS Errors and Application Issues

[Aaron.Kjos]

Hi,

I created a new application for AppD for my system's UAT environment. These are Windows Server 2019 IIS web and application servers with the .NET agent.

After installing the AppD .NET agent and having it running, it does report back to the controller, but we observed new errors in our application and the business process we are trying to run is failing with this:

Full Error Message: System.Net.WebException: The request was aborted: Could not create SSL/TLS secure channel.

If I disable AppD, then the process works and the TLS error goes away.   So AppD is actually causing an impact on our environment. Any ideas on how I can fix it?

[Ryan.Paredez]

Hi @Aaron.Kjos,

I found this info. I'm not sure if this totally matches up with what you are looking for. But let me know if it helps or at least helps you tackle the problem in a different way.

1) Navigate to C:\ProgramData\AppDynamics\DotNetAgent\Config
2) Open config.xml
3) At <controller> tag add enable_tls12="false" as an attribute.

<controller host="<HOST>" port="<PORT>" ssl="<false or true>" enable_tls12="false">

4) Save the file
5) Restart the "AppDynamics Agent Coordinator" service at services.msc
6) Restart the IIS

[Aaron.Kjos]

Ryan, thank you.

I think adding this enable_tls12="true" to the agent config.xml may actually be what I needed.

I'm testing that solution now.

Thanks!

[Ryan.Paredez]

Hi @Aaron.Kjos,

Follow up and let me know after your testing!

[Henrik.Juul]

I'm experiencing the exact same problem just with a .Net Console Application.

If I run it with the Agent running it fails - if I run it without the Agent running it works. What to do when the suggested solution doesn't work?

Best regards,

Henrik

[Ryan.Paredez]

Hi @Henrik.Juul,

I know you mentioned .Net App; I was not able to find any existing content related to that. I did find this SSL doc for the .net agent. Maybe some information there might be helpful still. 

https://docs.appdynamics.com/22.2/en/application-monitoring/install-app-server-agents/net-agent/inst...

If not, see if you can reach out to your AppD Account Manager for more specific help on this question.