Quick answer: Add the missing key to the active locale table, ensure the table is loaded before the dialogue queries it, and fall back to the default language rather than the raw key.
Seeing a key like DLG_INTRO_01 on screen means the lookup found nothing for the current language. Adding the entry and preloading the table fixes it. Here is how.
How to fix it
1. Add the missing key
Confirm the exact key exists in the active locale's string table; localization lookups are case- and whitespace-sensitive, so a stray space or wrong casing returns the key itself.
2. Preload the table
Load or await the locale string table before the dialogue starts requesting lines, so the first line does not query an empty table during the load.
3. Fall back to the base language
Configure the lookup to return the default-language string (and log a warning) when a key is missing for the current locale, so players never see raw keys.
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.