# Errors
Reference for the errors thrown by dotlottie-io, including password protection failures and invalid audio formats.

# Errors

`dotlottie-io`'s Node.js and Browser bindings throw regular JavaScript `Error` objects. This page lists the conditions that cause them.

## Password protection

| Message                                    | Cause                                                              |
| ------------------------------------------ | ------------------------------------------------------------------ |
| `"password required to open this archive"` | The archive is encrypted, but no `password` argument was provided. |
| `"wrong password or corrupted archive"`    | The provided password is incorrect, or the archive is corrupted.   |

```javascript
try {
  DotLottie.fromBytes(protectedBytes);
} catch (e) {
  console.error(e.message); // "password required to open this archive"
}
```

See [How to Password-Protect a .lottie File](/docs/tools/dotlottie-io/guides/password-protecting-files).

## Invalid audio format

`addAudio` (on [`DotLottie`](/docs/tools/dotlottie-io/api/dotlottie-class#addaudiofilename-data--getaudiofilename--audiofilenames) and [`DotLottieBuilder`](/docs/tools/dotlottie-io/api/dotlottie-builder-class#adding-content)) throws `InvalidAudioFormat` if `filename` doesn't end in `.mp3`. This is the only supported audio format.

## Unknown ID on removal

`removeAnimation`, `removeTheme`, and `removeStateMachine` all throw if the given `id` doesn't exist in the package. There's no silent no-op for a missing ID — check `animationIds()`/`themeIds()`/`stateMachineIds()` first if you're not sure the ID is present.

## Merge collisions

When using [`DotLottieMerger`](/docs/tools/dotlottie-io/api/dotlottie-merger-class) or [`DotLottieBuilder.mergeStrategy()`](/docs/tools/dotlottie-io/api/dotlottie-builder-class#mergestrategystrategy) with `MergeStrategy.Fail`, `merge()`/`build()` throws on the first ID or filename collision encountered. See the [`MergeStrategy` table](/docs/tools/dotlottie-io/api/dotlottie-merger-class#mergestrategy) for how this differs from `Rename` and `Skip`.

## Builder validation

`DotLottieBuilder.build()` throws if any queued content is invalid — for example, a non-`.mp3` audio file queued via `addAudio`.