# CHECK_INVALID

> a check croft cannot run

**Error** · category **project** (the project has a mistake in an asset file, croft.json or the command line) · exit **2** (invalid project or usage)

A check croft cannot run.

A check is unique(a, b), not_null(a, b), min_rows(n), or one boolean SQL expression over the asset's columns
([`croft docs checks`](https://croft.zabaca.com/docs/guides/checks.md)). CHECK_INVALID means a check is none of those, or cannot run on this table:
- it does not parse, or it is several expressions (a `,` between them, or a `;`);
- a form of the check language inside a larger expression (not_null(a) OR b > 0), or a near miss such as
  notnull(a), which gets a did-you-mean;
- it names a column the asset does not have, or its types do not fit the data;
- it reads a file, calls a table function that reads files or runs SQL given as text, or uses a parameter.

A blocking check that cannot run stops the write as a failing one does: data a check cannot vouch for is not
committed. A warning that cannot run is reported, and the write stands.

What to do: correct the check in the asset file; the message quotes it, and the fix renames a misspelled
column. croft validate --json checks every check before a run, and binds each check of an SQL asset against the
columns its SELECT returns. Rewrite a check so it says what it meant; removing it instead needs the user's yes.

The same page is in the CLI: `croft docs CHECK_INVALID`.

Source: https://croft.zabaca.com/docs/reference/errors/check-invalid/