unknown unit "{unit}" in system "{system}"; ...

Warnings reference › unit:unit:*:*

Identifier

unit:unit:*:*

Raised by

The grid (core)

Since

1.0.1

What happened

The system exists and the base unit named in it does not. The column falls back to that system's base unit, so the numbers are interpreted in a different unit from the one you declared - the values themselves are unchanged, their meaning is not.

The fix

Use a symbol the system defines. The message names the unit it fell back to.

Reference

Covered in full at the API reference.