What causes the “insecure connection not allowed” exception in Unity?

The build is requesting a plain http:// URL while the player settings only allow HTTPS — Unity blocks cleartext HTTP by default (and iOS/Android add their own transport security rules).

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix “InvalidOperationException: Insecure connection not allowed” in Unity

Quick answer: Serve the endpoint over HTTPS and update the URL; only as a last resort relax 'Allow downloads over HTTP' in Player Settings, which stores and platforms increasingly reject.

Unity blocks cleartext HTTP requests in players by default, so a URL that worked in the editor throws this in a build. The right fix is HTTPS, not loosening the setting. Here is the path.

How to fix it

1. Find the offending URL

The exception message includes the URL. Grep your config and code for http:// — it is often one forgotten asset, telemetry, or update-check endpoint.

2. Put the endpoint behind TLS

Most hosts and CDNs give you HTTPS for free. Update the URL scheme and confirm the certificate chain is valid on device, not just desktop.

3. Understand the platform layers

Even if Unity allows HTTP, iOS App Transport Security and Android cleartext policy will still block it — HTTPS is the only setting that works everywhere.

4. Keep the strict default

Leaving 'Allow downloads over HTTP' at its strict setting protects players on hostile networks and passes store review; treat any HTTP dependency as a bug.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.