# X_SIDE_EFFECTS_ENTRY_STALE

## Means

a declared `sideEffects` entry matches no file in the package

## Typical cause

the file it named was renamed or deleted, so the entry protects nothing while still reading as a rule in force

## Fix

delete that entry from `"sideEffects"` in the package's `package.json`, or point it at the file it was written for

[CLI and verify](/error-codes#cli-and-verify)