Xrmtoolbox The Underlying Connection Was Closed

Xrmtoolbox The Underlying Connection Was Closed

XrmToolbox is a popular tool used by Microsoft Dynamics CRM users to manage and customize their environments. It provides a wide array of plugins to facilitate administrative tasks, streamline customization processes, and improve overall efficiency. However, like any software, XrmToolbox can sometimes encounter errors, one of which is the "The Underlying Connection Was Closed" error. This error can be frustrating, especially when working on time-sensitive projects or managing multiple Dynamics CRM instances.

In this topic, we will explore the causes of the "The Underlying Connection Was Closed" error in XrmToolbox and provide practical solutions to fix the issue. Whether you’re a seasoned CRM administrator or a beginner, understanding the root causes and solutions will help you navigate through this problem effectively.

What is XrmToolbox?

Before diving into the error, it’s helpful to understand what XrmToolbox is and why it’s used in the first place. XrmToolbox is a Microsoft Dynamics CRM/365 tool that acts as a front-end interface for interacting with your CRM environment. It supports various plugins that make administrative tasks more manageable, such as managing security roles, importing and exporting data, and customizing entities. XrmToolbox is widely used because it simplifies tasks that would otherwise require complex code or multiple steps within the CRM system.

However, users may occasionally run into technical issues while using the tool, and one common issue is the "The Underlying Connection Was Closed" error.

Understanding the ‘The Underlying Connection Was Closed’ Error

When using XrmToolbox, you may encounter the error message: "The underlying connection was closed: An unexpected error occurred on a send." This error typically occurs when trying to connect to a Microsoft Dynamics CRM server or when trying to send or receive data. It indicates that the connection to the server was unexpectedly closed, which can prevent you from accessing your CRM data or using various features of XrmToolbox.

Why Does This Error Happen?

There are several potential causes of the "The Underlying Connection Was Closed" error. These causes can range from server issues to network configuration problems. Some of the most common reasons include:

  1. SSL/TLS Version Mismatch: Modern web applications, including XrmToolbox, use Secure Socket Layer (SSL) or Transport Layer Security (TLS) to establish secure connections. If your server is using an outdated SSL/TLS version that is incompatible with XrmToolbox, it can lead to the connection being closed unexpectedly.

  2. Timeout Issues: If your network is slow or there are connectivity issues, the server may not respond within the time frame specified by XrmToolbox. This can result in a timeout error and cause the connection to be closed.

  3. Proxy or Firewall Restrictions: A misconfigured proxy or firewall can block the communication between XrmToolbox and the Dynamics CRM server. This could lead to the connection being abruptly closed.

  4. Server-Side Configuration: Sometimes, server-side settings, such as session timeouts or connection limits, can cause connections to be closed prematurely. This may occur when the server is under heavy load or experiencing resource issues.

  5. Plugin-Specific Errors: Certain plugins within XrmToolbox might be causing issues with the connection. If a particular plugin is outdated, incompatible, or poorly configured, it can interfere with the overall connection to the server.

  6. Network Connectivity Issues: Poor or unstable internet connections can also lead to connection problems. This can be especially problematic if you are working remotely or on a less reliable network.

How to Fix the ‘The Underlying Connection Was Closed’ Error

Now that we understand the potential causes, let’s explore some of the solutions to fix the "The underlying connection was closed" error. Follow these steps to resolve the issue:

1. Update SSL/TLS Settings

If the error is related to SSL/TLS version incompatibility, the first step is to ensure that both your CRM server and XrmToolbox are using supported versions of SSL or TLS. Microsoft Dynamics CRM now requires TLS 1.2, which is the most secure and compatible version.

How to Check and Update SSL/TLS Settings:

  • Open the Internet Options on your computer.

  • Go to the Advanced tab and scroll down to the Security section.

  • Make sure that TLS 1.2 is enabled. You may need to disable older versions like SSL 3.0 and TLS 1.0 to avoid compatibility issues.

  • If you’re the CRM administrator, ensure that your server supports and forces TLS 1.2 for secure connections.

2. Increase Timeout Settings

If the issue is related to timeouts, you can try adjusting the timeout settings in XrmToolbox to give the tool more time to establish a connection. Here’s how you can increase the timeout:

  • Open XrmToolbox.

  • Go to Settings > Options.

  • Find the Timeout setting and increase the value (e.g., from 30 seconds to 60 seconds).

  • Save the settings and try reconnecting to your Dynamics CRM environment.

This can help if the issue is due to network latency or slower server response times.

3. Check Proxy and Firewall Configuration

Ensure that your firewall or proxy server is not blocking the communication between XrmToolbox and your Dynamics CRM server. If you are using a proxy, you may need to configure the proxy settings in XrmToolbox:

How to Configure Proxy Settings in XrmToolbox:

  • Open XrmToolbox.

  • Go to Settings > Options.

  • Under the Proxy tab, enter your proxy settings if needed.

  • Test the connection again to see if the error is resolved.

If you are unsure about your proxy or firewall settings, consult with your IT team or network administrator to ensure the necessary ports and protocols are open for communication.

4. Review Server-Side Configuration

If the issue is occurring on the server side, you may need to check the server’s session timeout and connection settings. Ensure that the server is not set to automatically close idle connections too quickly. Check your Dynamics CRM server for any resource limitations, such as memory or processing constraints, which may be causing connection drops.

5. Update or Disable Problematic Plugins

Sometimes, specific plugins in XrmToolbox may cause the connection error. If you suspect that a particular plugin is the culprit, try disabling it or updating it to the latest version. Here’s how you can manage plugins:

  • Open XrmToolbox.

  • Go to Plugins > Plugin Store.

  • Search for the plugin that might be causing the issue.

  • If an update is available, click Update.

  • If not, try disabling the plugin temporarily to see if the issue resolves.

6. Test Network Connectivity

If you are experiencing connectivity issues, make sure that your network connection is stable. If possible, test the connection using a different network (such as a different Wi-Fi network or a wired connection) to rule out network instability as the cause of the error.

The "The Underlying Connection Was Closed" error in XrmToolbox can be caused by several factors, ranging from SSL/TLS version mismatches to network or server configuration issues. By following the troubleshooting steps outlined in this topic, you should be able to resolve the error and restore connectivity to your Dynamics CRM environment.

If the problem persists despite troubleshooting, it may be worth reaching out to Microsoft support or your system administrator for further assistance. Properly maintaining your server’s configuration, ensuring that you are using the latest versions of XrmToolbox and its plugins, and configuring your network settings correctly will go a long way in preventing this error from occurring in the future.