Fix ERR_CERT_AUTHORITY_INVALID on Coolify
Error: NET::ERR_CERT_AUTHORITY_INVALID
The browser reached your server but the TLS certificate is not trusted.
On Coolify this almost always means the domain is missing from the app config, or the domain is set as http:// instead of https:// — so Traefik never asked Let’s Encrypt for a real cert and is serving its self-signed default.
The fix
Open your app in Coolify → Settings → Domains. Confirm the exact domain you are visiting is listed.
Make sure it is set as https:// (not http://). An http:// domain silently skips cert issuance.
Confirm DNS already points at your VPS before redeploying — Let’s Encrypt cannot issue until the domain resolves to the server.
dig +short your-domain.com @8.8.8.8 # should return <your-vps-ip>Redeploy the app. The cert usually issues within ~60s of the first request after DNS resolves.
Verify it worked
A valid cert returns "SSL certificate verify ok":
curl -sv --max-time 10 https://your-domain.com 2>&1 | grep "subject\|SSL cert\|HTTP/"Related Coolify errors
- TRAEFIK DEFAULT CERT / self-signed certificate
- acme: error: 429 :: POST :: too many certificates already issued for exact set of domains, retry after ...
- unable to obtain ACME certificate for domains "your-domain.com": unable to generate a certificate for the domains [your-domain.com]: error: one or more domains had a problem: [your-domain.com] acme: error presenting token / authorization failed
- ERR_TOO_MANY_REDIRECTS — This page isn't working. your-domain.com redirected you too many times.