While sending events to your Snowplow collector, whether on production or testing, you may from time to time encounter cases where the client has blocked a specific request.
Confirm the error
You can verify the error by viewing your browser's Developer Console. In the Console tab, look for errors highlighted with a red background matching the below format.
GET https://example.com net::ERR_BLOCKED_BY_CLIENT
Browser tracking prevention
Particular browsers (namely Microsoft Edge) can have Tracking Prevention enabled. If this is set to Strict it's possible that they will block third-party Snowplow tracking endpoints. This most commonly affects the Snowplow Mini endpoint.
You can check your Tracking Prevention settings in Microsoft Edge by following this Microsoft guide. If you set it to Balanced or Basic this should resolve the problem.
Ad blockers
Alternatively, your issue may be caused by a third-party ad blocker. Please disable ad blockers on the environment you're testing your Snowplow tracking on and review the results.