Troubleshooting

This guide aims to extend the main troubleshooting guide by covering Replay-specific scenarios.

My canvas Elements Aren't Getting Captured

There's currently no support for canvas. It's being tracked in this GitHub issue. Feel free to 👍 and help us prioritize it.

My Custom CSS/Images/Fonts/Media Aren't Appearing When I View the Replay

The replay 'video' is actually a video-like reproduction of the HTML on your website. This means that all the external resources your site uses (CSS/Images/Fonts), will be rendered by the corresponding <style>, <img> and <video> tags on your site. Add sentry.io to your CORS policy so the iframe hosted on sentry.io can fetch and display these resources.

Why can't I see the full HTTP request body or all the headers?

By default, Replay will capture basic information about all outgoing fetch and XHR requests in your application. This includes the URL, request and response body size, method, and status code. The intention is to limit the chance of collecting private data. You can configure the SDK to capture bodies and additional headers.

Another reason you might not see the body is if the format is not supported. We only capture text-based bodies, including JSON, XML, FormData, and similar data types. Any captured body will be truncated to 150k characters. When we identify the body as JSON, we will try to truncate it while keeping the payload valid JSON. Bodies of byte, file, or media types are not captured.

More details about this feature can be found in the configuration page.

Text in the iframe isn't masked

Our masking logic doesn't run on iframe content that's provided using the srcdoc attribute, rather than loaded in via src.

To hide this content, block the iframe, as described in our Session Replay Privacy docs.

Replay on My Browser Extension Doesn't Work

This is not a supported use-case. The replay package is built to work on a website and not as an externally-loaded script via browser extension or other mechanism. In fact, Sentry's Session Replay product can help developers find out when a third-party Chrome extension causes otherwise hard to debug or reproduce issues with their website.