# Could not transfer artifact com.example:lib:1.0.0 from/to central (https://repo.maven.apache.org/maven2): Received fatal alert: certificate_unknown. The repository mirror at https://internal-mirror.com/maven2 may be misconfigured.

- **ID:** `java/maven-repository-mirror-loop`
- **Domain:** java
- **Category:** network_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The SSL certificate of the mirror repository is not trusted by the Java runtime, or the mirror is misconfigured.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 8+ | active | — | — |

## Workarounds

1. **Import the mirror's SSL certificate into the Java truststore** (95% success)
   ```
   keytool -import -alias mirror -keystore $JAVA_HOME/lib/security/cacerts -file mirror.crt
   ```
2. **Use HTTPS with a trusted certificate or switch to HTTP if allowed** (90% success)
   ```
   <mirror><id>internal</id><url>http://internal-mirror.com/maven2</url><mirrorOf>central</mirrorOf></mirror>
   ```

## Dead Ends

- **Disabling SSL verification globally in settings.xml** — This is a security risk and may not be allowed in corporate environments. (80% fail)
- **Using a different mirror without verifying its certificate** — The new mirror may have the same issue or be malicious. (90% fail)