Quick answer: Validate platform tokens server-side against each provider, map them to your account identity, and handle each platform's quirks so sign-in is secure and reliable.
Trusting a client's platform token invites spoofing. Server-side validation makes sign-in secure. Here is how.
How to fix it
1. Validate tokens server-side
Verify each platform's token with the provider on your backend, never trusting the client alone.
2. Map to your identity
Link the validated platform identity to your account system so platforms unify into one player.
3. Handle platform quirks
Account for each provider's token formats, refresh, and policy requirements.
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 backend 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.
The bug you can't reproduce isn't gone — it's just invisible until you capture it from the player's device.