# Troubleshooting

URL: https://docs.nolay.ru/en/troubleshooting/
Updated: 2026-09-23

> Common symptoms, their causes and what to do without contacting support.

Find the symptom in the table. If the panel shows an error code, look it up in the [error reference](/en/reference/errors/).

## Server

| What you see | Why | What to do |
|---|---|---|
| The server is Offline | The agent is stopped or there is no outgoing access to `api.nolay.ru:443` | `systemctl status nolay-agent`, then `journalctl -u nolay-agent -n 50` |
| Offline after reinstalling the OS | Another agent or an old token on the server | Delete the server in the panel and [connect it again](/en/start/connect-server/) |
| Disk over 85 percent | Old images take space | `docker image prune`, or grow the disk |

While the server is offline, its projects keep running.

## Deploy

| What you see | Why | What to do |
|---|---|---|
| Deploy failed | The build broke | The last lines of the build log name the cause. The previous version keeps running |
| Readiness check failed | The app did not answer on the port | Check the port and that the app listens on `0.0.0.0`, not `127.0.0.1` |
| Stack not recognized | No `Dockerfile`, and the files do not look like a known stack | Add a `Dockerfile` or pick a builder in [`builder`](/en/reference/nolay-toml/#field-builder) |
| The build ran out of memory | The server did not have enough memory | Set [`resources.mem_mb`](/en/reference/nolay-toml/#field-resources-mem_mb) or use a 2 GB server |

## Domain

| What you see | Why | What to do |
|---|---|---|
| Running, but unreachable from outside | DNS does not point at the server yet, or ports 80 and 443 are closed | Check `dig +short A <domain>` and the provider firewall |
| No certificate | DNS is not ready, Let's Encrypt cannot verify the domain | See `docker logs nolay-caddy`, retry only after fixing DNS |

More in [Domains and HTTPS](/en/guides/domains/).