What it means
Extensions inject scripts into the pages your visitors open: password managers, ad blockers, translators, shopping assistants. When their code throws, the error fires on your page and your SDK reports it.
You can tell by the stack: every frame points at chrome-extension://, moz-extension:// or safari-web-extension:// instead of your own domain.
Is it a real bug?
Not in your code. You cannot fix it and the visitor usually notices nothing. The exception is an extension breaking your page, which shows as errors with both extension frames and your own frames, and those stay in.
How to filter it
For any Sentry-compatible browser SDK:
Sentry.init({
dsn: "...",
denyUrls: [/^chrome-extension:\/\//, /^moz-extension:\/\//, /^safari(-web)?-extension:\/\//],
});In RealUptime Errors
You do not need the filter above. RealUptime Errors drops this error by default, before it reaches your quota, and counts every drop on the issue list so nothing disappears silently. What we match: An event whose every stack frame comes from a browser extension URL. One frame from your own site keeps it.
To see these errors anyway, turn off the noise filter for a project in Errors settings. It works the same for the RealUptime SDK and for Sentry SDKs pointed at RealUptime.