---
title: Update errors
description: Why an NexCMP update can fail — entitlement, download verification, signature, restart — and how to recover or roll back.
url: https://nexcmp.com/docs/troubleshooting/update-errors/
applies_to: NexCMP 1.6.1
updated: 2026-11-02
---

# Update errors

> **Where in the admin:** System › Admin › License & updates (`/license`)

Updates are described in [Updating NexCMP](https://nexcmp.com/docs/getting-started/updating/). When the Update card or `sudo nexcmp update` reports an error:

| Message | Cause | Fix |
|---|---|---|
| `update plan expired — renew on the license page to receive this feature release` | Your "updates until" date is before the release date. Security fixes are still delivered; feature releases are not | Renew at [nexcmp.com/licenses](https://nexcmp.com/licenses) ($99 per year for NexCMP Free), then check again. The software keeps running meanwhile. |
| `sha256 mismatch (downloaded …, expected …)` | Damaged or altered download | Retry. If it repeats, check proxies on the path. |
| `downgrade/same version rejected: X is not newer than Y` | The selected version is not newer than the running one | Nothing to do — you are up to date. |
| `extraction failed / main binary missing` | Damaged archive or full disk | Check `df -h`; retry. |
| `systemctl restart failed` | The service could not restart after replacing the binary | `journalctl -u nexcmp -n 80`; the previous binary is kept as `/opt/nexcmp/bin/nexcmp.bak` — see roll back below. |
| Server error contacting the update server | No route to `nexcmp.com` or license token expired | Check outbound HTTPS; click **Check now** on the License card. |

## Roll back

If a new version misbehaves:

```bash
sudo systemctl stop nexcmp-vmd nexcmp
sudo cp /opt/nexcmp/bin/nexcmp.bak /opt/nexcmp/bin/nexcmp
echo <previous-version> | sudo tee /opt/nexcmp/VERSION
sudo systemctl start nexcmp nexcmp-vmd
```

If a database migration already ran, restore your [backup](https://nexcmp.com/docs/getting-started/backup-and-restore/) taken before the update as well.

## `sudo nexcmp update` says it cannot find the installer

`nexcmp update` runs the installer that ships inside the installed release (`/opt/nexcmp/releases/<version>/share/install.sh`). If that file is missing, run the install command from your license page again.