# E3100

Compiler diagnostic name: `invalid_mbti`.

The package interface file is invalid.

An `.mbti` file describes the public interface of a package. MoonBit reports
this error when the file cannot be parsed as a valid interface file.

This is the parser error for invalid interface-file syntax. The warning table
also contains `E0047` with the same diagnostic name, but current `.mbti` syntax
errors are reported through this compiler error.

## Erroneous example

```{literalinclude} /sources/error_codes/3100_error/pkg.mbti
:language: moonbit
:caption: pkg.mbti
```

## Suggestion

Regenerate the interface with `moon info`, or edit it so it contains valid
interface declarations.

```{literalinclude} /sources/error_codes/3100_fixed/pkg.mbti
:language: moonbit
:caption: pkg.mbti
```