This topic discusses some issues you may encounter when installing the .NET Agent. 

Verify Agent Controller Communication

Use the AppDynamics UI to verify that the agent can connect to the Controller.

  1. In a browser open:


    If you cannot connect to the controller in Internet Explorer, see Check Internet Explorer proxy settings.

  2. Log in to the AppDynamics UI.
  3. Select the application to open the Application Dashboard.
  4. In the left navigation panel click Servers > Tiers & Nodes and open the Health tab.

The Health tab lists the tiers, their nodes, and App Agent Status. When an agent successfully reports to the Controller, you see an up arrow symbol.

For details see Agent-to-Controller Connections.

  • When deploying multiple agents for the same tier, determine whether you get the correct number of nodes reporting into the same tier.
  • After sending a request to your web application, data should appear on the AppDynamics UI. The agents should display in the Application Flow Map of the Application Dashboard.

If no data appears after a few minutes:

  • Verify that the Agent is writing its log files:
    Windows Server 2008 and later: %ProgramData%\AppDynamics\DotNetAgent\Logs\AgentLog.txt
  • If the log file exists, open it and review it for errors.
  • If the log file does not exist, run the Windows Event Viewer and see the application messages.
  • If there are no AppDynamics event messages, look for messages from the .NET Runtime.

Check Internet Explorer proxy settings

This section is only for resolving issues connecting to the AppDynamics Controller when step 1 of 'Verify Agent Controller Connection' above fails. To configure the .NET Agent to work through a proxy, see 'Controller Element' on .NET Agent Configuration Properties.

Misconfigured proxy settings in Internet Explorer may cause the App Agent for .NET to fail to connect to the controller. If Test Controller connection fails on the Controller Configuration window in the AppDynamics Agent Configuration utility, do the following:

  1. Verify the Controller host and port settings are correct.
  2. In Internet Explorer, open:

  3. If the connection also fails in Internet Explorer, check the proxy settings.  See Change IE Proxy Settings.
  4. Correct or remove any incorrect proxy settings.

Checklist for Resolving .NET Agent Installation Issues




Run the installer as Administrator.

Verify Administrative privileges

(tick)Verify that MSDTC is enabled and that it is running under the correct account.Verify MSDTC is enabled and running under the correct account


Verify permissions for Agent directory.

Verify that the .NET Agent directory has the correct permissions based on the site’s application pool identity.


Verify that the Agent is compatible with the Controller.

Agent and Controller Compatibility


Verify the correct settings in the config.xml:

Windows Server 2008 and later:

Update the config.xml file to include the .NET Agent Configuration Properties.

Resolve .NET Agent Installation Issues

If the Agent installation is failing, check the following configurations in your environment:

Verify administrative privileges

Ensure that you have the administrative privileges when you launch the installer. If the current user doesn't have sufficient privileges, the installer prompts you for an administrator password.

Verify MSDTC is enabled and running under the correct account

If you encounter an error that MSDTC is not enabled or it is running under the wrong account, launch an elevated command prompt with full administrative privileges and execute the following command:

msdtc -install

Even if MSTDC is already installed, this command resets the service to run using the "NT Authority\NetworkServices" account.

Generate a log for agent installation failures

If the installer fails, use the command line utility to launch the installer.

msiexec /i $Path_to_the_MSI_File /l*v verbose.log

A verbose log for the .NET Agent is created at the same location where you saved the installer file.

Correct failed installation caused by other APM products

The .NET Agent installation may fail if there are other Application Performance Management (APM) products installed in the same managed environment. Remove the associated Environment subkey for certain services for the installed APM products.

Remove associated Environment subkey for W3SVC and WAS services in the registry:

  1. Run Regedit or regedt32.
  2. In regedit.exe, locate the following registry keys: 
  3. Expand the keys.
  4. Modify the Environment subkey to delete the following values:

        COR_PROFILER= {a GUID}
  5. Restart the services. For more details see How to restart the W3SVC and WAS services?

Resolve Configuration Errors

  • Set your IIS applications to a Full trust level. .NET Agent reporting will not work if an IIS application is set to anything other than a Full trust level.
  • Ensure that you have correctly configured the config.xml file for the App Agent for .NET. For more detail, see .NET Agent Configuration Properties.
  • If you made manual edits to the config.xml file, check the AgentLog.txt and file  WarnLog.txt file for errors. Invalid XML shows in the log as follows:

    2014-03-13 10:49:18.7199 1232 dllhost 1 1 Error ConfigurationManager Error reading the configuration file
  • Resolve Log Issues

The .NET Agent writes logs to the following directories: 


The agent will not generate logs if the agent directory does not have sufficient permissions.

Verify that the .NET Agent directory has the correct permissions

  1. Click IIS > Application pools.
    IIS displays the list of application pools for your machine.
  2. Right-click a particular application pool.
  3. Click Advanced Settings.

    IIS displays the Application Pool Identity for that application.
  4. Ensure that your Agent Directory also has the same permissions as your site application pools.
    • Navigate to AppDynamics .NET App Server Agent directory location.
    • Right-click on the logs directory for the App Server Agent and select Properties.

    • Click the Security tab and verify that the same Application Pool Identity is specified for the .NET Agent directory.

If the Agent logs directory does not have the required permissions:

  1. In the Security tab, click Edit.
  2. Click Add to add new permissions to the Agent directory.
  3. Click Advanced.
  4. Click Find Now to find all the users, groups, or built-in security principals on your machine.
  5. Select the required group from the list and click OK. See the information that follows for Allowed groups
  6. Provide the read and write permissions for the selected user/group/security principal to the Agent directory and click OK.
  7. Click Apply.

Allowed groups for different IIS versions

For IIS v6.x, following settings are applicable for Application Pool Identities:

Application Pool Identity

Permission Level







Custom Account

Provide the exact name of the account.

For IIS v7.0 and later, following settings are applicable for Application Pool Identities:

Application Pool Identity

Permission Level








Provide the group level permissions for IIS_IUSRS Group
See the screenshot that follows

Custom Account

Provide the exact name of the account.

For example, if your application has the identity ApplicationPoolIdentity, you must provide the permissions for IIS_IUSRS group to your agent directory.


Another Version of AppDynamics Detected

AppDynamics recommends that you contact support to resolve this issue.

The .NET Agent versions 20.3 and later supports .NET Core. If you used the Microservice Agent to monitor .NET Core applications you can monitor .NET Core with the full .NET Agent. You may receive an error message in the MSI Installer stating that another version of AppDynamics is detected. 

The Microservice Agent uses a JSON file to store configuration information while the .NET Agent uses an XML file. The data does not migrate between these files. 

To fix this issue, you need to map the data in the JSON file to the XML file, config.xml and remove environment variables. If you have completed the instructions above and still see the error, you may need to reboot your machine. You may want to plan reboots according to your planned outage schedule. 

Known Issues

You may ignore the following error from the AppDynamics.Agent.Coordinator service in the agent.log or warn.log:

2015-12-01 10:12:03.0435 3872 AppDynamics.Coordinator 1 7 Warn MaxQueueItemAgePolicy MaxQueueItemAge is beyond the integer limit: 13093467123