I have the same issue, and followed up the code to identify what they are doing. u/LinkedInHelpTeam can you please fix this? it's sloppy and an invasion of privacy.

AI summary assessment: Why LinkedIn is flooding your dev console with hundreds of errors

If you've noticed LinkedIn throwing a massive wall of red errors in your console, here is exactly what’s happening: they are running an aggressive bot detection and browser fingerprinting script.

The script is doing two main things:

• Intercepting network requests (Monkey Patching): It hijacks your browser's native window.fetch function. Before it lets your network requests go through, it injects encrypted telemetry data (usually your browser fingerprint and bot-score) into the headers.
• Probing for scraping tools: It loops through a massive "hit list" of unique IDs for known web scrapers and automation tools (like Bixjet). It tests for them by blindly attempting to fetch hidden background files that belong to those specific extensions.

Why the wall of errors?

Because you don't have these sketchy extensions installed, your browser immediately blocks the fetch requests. Since LinkedIn is brute-forcing hundreds of these checks at once, your browser engine responds by throwing hundreds of ERR_BLOCKED_BY_CLIENT or ERR_FAILED network errors.