What causes numbers using the wrong decimal and thousands separators?

You build number strings manually with a hardcoded period decimal and comma grouping, ignoring that many locales swap those separators.

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 Numbers Showing a Period Decimal in Comma-Decimal Locales

Quick answer: Format numbers through a locale-aware formatter (Intl.NumberFormat, CultureInfo, or your engine's equivalent) instead of concatenating digits by hand.

German and many other locales write 1.000,5 not 1,000.5. Hardcoded separators look broken to those players. A locale formatter fixes it. Here is how.

How to fix it

1. Format with a locale-aware API

Pass the raw number and the active locale to a formatter such as Intl.NumberFormat(locale) or number.ToString("N", culture) rather than assembling the string yourself.

2. Never store formatted numbers

Keep numbers as numeric types in data and save files, and only format at display time, so the locale separator never leaks into persisted values.

3. Test grouping in several locales

Verify large numbers in locales that use space, period and comma grouping, since each renders the same value differently and exposes hardcoded assumptions.

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 HTML5 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.