Issues involving WebSockets

What is WebSocket?

WebSocket is a computer communications protocol that enables messages to be sent to and from the server. Basically, it is a means of communication between you and the server. The WebSocket specification defines an API for establishing "socket" connections between a web browser and the machine. In other words, there is a persistent connection between you and the server, and both sides of the connection can start sending data at any time. The XTM Workbench application uses WebSockets to establish the connection.

The WebSockets are quite sensitive to some online software that has the potential to affect the connection. Sometimes, the direct cause of the WebSockets disconnections is the software installed on the user end, such as:

  • browser plugins/extensions,

  • firewalls,

  • VPNs (Virtual Private Network),

  • CDNs (Content Delivery Network).

If the disconnects occur, it is always a good idea to temporarily disable the software and see if that helps. If that does not yield the required results, see XTM Workbench – most common issues & troubleshooting and follow the basic steps described in the article.


Generally, there are a few issues involving WebSockets. Below are the most common cases:


The JSERROR (or JavaScript Error) is usually an issue with a user'’s browser but it might sometimes also be caused by an XTM Cloud front-end bug. To be certain, though, proper investigation is required. As a user, you can help the XTM International Support team by providing the relevant information, to speed up issue resolution.

The error in the browser developer tools usually points to some JavaScript files, indicating that required properties cannot be read. A blank screen might then be displayed instead of the Workbench application, as in the example below:

Browser developer tools - the Console section:

See How to use browser's developer tools (Dev Tools) for help.


The NO_BROWSER_PING issue occurs when the XTM Cloud application cannot ping the browser anymore, which leads to the WebSockets disconnection. This is usually a user-end issue, and the connection between the browser and XTM Workbench can be blocked by, for example, some software.

Below is the XTM Workbench window with the browser developer tools errors: the Console section:

WebSockets can be tested with online tests: WebSocket tester.

Good to know!

In most cases, WebSockets issues occurring on the user-end and the XTM International Support team is often unable to directly solve such issues. However, the problems sometimes only seem to lie at the users end, but it eventually turns out that an XTM Cloud issue is involved and we need to make some changes. No matter what the root cause is, do not hesitate to contact the XTM International Support team with all the above-mentioned information.