Quick answer: Persist every completed-but-unverified receipt to a durable queue and replay the verification with backoff once connectivity returns.
A player completes a store purchase in airplane mode; the store grants it but your backend verification fails and you drop the receipt, so the entitlement is lost. A durable replay queue fixes it.
How to fix it
1. Queue receipts durably
When verification fails due to network, write the receipt/token to persistent storage rather than discarding it, so it survives a restart.
2. Replay on reconnect
When connectivity returns, drain the queue and re-attempt verification with backoff, granting the entitlement only after the backend confirms.
3. Reconcile with the store
On launch also re-query the store for owned/unfinished transactions so a purchase the queue missed is still recovered.
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 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.
Most of the time the fix is small. Seeing the failure clearly is the part that actually costs you.