Troubleshoot - Error -20151 — Unauthorized Device Clone Detected
What does error -20151 mean?
The error -20151: Unauthorized device clone detected indicates that the license system has identified abnormal behavior suggesting that the same license is being used on what appears to be a cloned or altered device environment.
This is a security protection mechanism designed to prevent license misuse.
🔍 Common Causes
1️⃣ System Time Was Modified
If the system date or time was manually changed (for example, rolling the clock backward or forward), the license validation logic may interpret this as a potential cloning or tampering attempt.
Typical scenarios include:
- Manual system time adjustment
- Time rollback after OS restore or snapshot
- VM snapshot restore with outdated system time
2️⃣ Switching SDK Versions Within a Short Period of Time
Rapidly switching between different SDK versions (for example, upgrading and downgrading, or running multiple major versions back-to-back) within a short timeframe can also trigger this error.
This may happen when:
- Testing multiple SDK versions on the same machine
- Running parallel applications using different SDK versions
- Rolling back to an older version shortly after upgrading
The license system may treat this as an abnormal environment change.
✅ Recommended Solutions
- Ensure the system time is correct and synchronized with an official time source.
- Avoid frequently switching between different SDK versions on the same device.
- If testing multiple versions is required, allow sufficient time between version changes.
- Restart the system after correcting time settings or completing upgrades.
📩 Still Experiencing the Issue?
If the issue persists after verifying the above:
- Please contact our support team.
- Provide your license key, SDK version, and a brief description of your environment and recent changes.
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