# The error `asset.manifest`

**user**: the script can change it: the error says what happened in the experiment's names, and what to write instead.
**environment**: something the run needs is missing or different where it runs (a package, a file, a device, the network): the error names what to install, fetch or attach.

Where MIME gives it, with what its message says happened and what its action says to do (`{…}` is filled in from the experiment):

- in `mime/assets/_manifest.py`:
  - what happened: `the manifest {…}: {…}`
  - what to do: `write it as {…}: format, name, title, credit, notice, assets (records) and files (each path a description writes, with its record's name); 'mime assets sources <manifest file>' reads it`
- in `mime/assets/_sources.py`:
  - what happened: `{…} (the source {…}) is neither a manifest nor a list of records under "assets"`
  - what to do: `correct the package's file, or uninstall the package that ships it: 'pip uninstall <package>'`

Reading an error and reaching its full traceback: [reading an error](../reading_errors.md). Every code: [the index](index.md).