# SYNC301: Sync behind head

## What this means[​](#what-this-means "直接链接到 What this means")

Some older store changes were skipped and must be downloaded again.

Run a targeted download for the affected data and export diagnostics if the gap remains.

## What to do[​](#what-to-do "直接链接到 What to do")

Restart WCPOS; if this keeps happening the local data on this device needs repair. WCPOS does not retry this by itself — retry when you are ready.

## Your data[​](#your-data "直接链接到 Your data")

Data on this device may be at risk — do not clear local data. If this persists, export diagnostics and contact WCPOS support.

## Details[​](#details "直接链接到 Details")

* **Code:** `SYNC301` (`SYNC_BEHIND_HEAD`)
* **Severity:** warn
* **Introduced in:** WCPOS 1.10.0