From bd33ab50e460b31830a3727628d11161d7e06b3a Mon Sep 17 00:00:00 2001 From: yqz562 <158135022+yqz562@users.noreply.github.com> Date: Wed, 4 Feb 2026 10:31:54 +0800 Subject: [PATCH 1/4] fix --- barcode-reader/web/index.md | 1 - barcode-reader/web/scan-setting/index.md | 1 - .../enable-supported-barcode-format.md | 0 license/index.md | 1 + ...ting-unauthorized-device-clone-detected.md | 57 +++++++++++++++++++ 5 files changed, 58 insertions(+), 2 deletions(-) rename {barcode-reader/web/scan-setting => license}/enable-supported-barcode-format.md (100%) create mode 100644 license/troubleshooting-unauthorized-device-clone-detected.md diff --git a/barcode-reader/web/index.md b/barcode-reader/web/index.md index af830b4..a014e46 100644 --- a/barcode-reader/web/index.md +++ b/barcode-reader/web/index.md @@ -62,7 +62,6 @@ Welcome! Browse the sections below for answers to common questions, configuratio - [Difference between BestSpeed and BestCoverage](scan-setting/difference-between-bestspeed-and-bestcoverage.html) - [Differences between Full and Compact Editions](scan-setting/differences-between-full-and-compact-editions.html) - [Differences between updateScanSettings, updateVideoSettings, and updateRuntimeSettings](scan-setting/differences-between-updateScanSettings-updateVideoSettings-and-updateRuntimeSettings.html) -- [Troubleshooting - Error: [xxx] No license found](scan-setting/enable-supported-barcode-format.html) - [Read Inverted Image](scan-setting/read-inverted-image.html) - [Remove Duplicates](scan-setting/remove-duplicates.html) - [Unable to Scan Aztec Code](scan-setting/unable-to-scan-aztec-code.html) diff --git a/barcode-reader/web/scan-setting/index.md b/barcode-reader/web/scan-setting/index.md index 115fb1f..18922c5 100644 --- a/barcode-reader/web/scan-setting/index.md +++ b/barcode-reader/web/scan-setting/index.md @@ -13,7 +13,6 @@ noTitleIndex: true - [Difference between BestSpeed and BestCoverage](difference-between-bestspeed-and-bestcoverage.html) - [Differences between Full and Compact Editions](differences-between-full-and-compact-editions.html) - [Differences between updateScanSettings, updateVideoSettings, and updateRuntimeSettings](differences-between-updateScanSettings-updateVideoSettings-and-updateRuntimeSettings.html) -- [Enable Supported Barcode Format](enable-supported-barcode-format.html) - [Read Inverted Image](read-inverted-image.html) - [Remove Duplicates](remove-duplicates.html) - [Unable to Scan Aztec Code](unable-to-scan-aztec-code.html) diff --git a/barcode-reader/web/scan-setting/enable-supported-barcode-format.md b/license/enable-supported-barcode-format.md similarity index 100% rename from barcode-reader/web/scan-setting/enable-supported-barcode-format.md rename to license/enable-supported-barcode-format.md diff --git a/license/index.md b/license/index.md index 93f20e0..db0a24b 100644 --- a/license/index.md +++ b/license/index.md @@ -20,3 +20,4 @@ Please use the links below to find answers to common questions and configuration - [How to track license usage?](track-license.html) - [New license required for per-device licensing?](new-license-required-per-device-licensing.html) - [How to get a free trial?](dbr-free-trial.html) +- [Troubleshooting - Error: [xxx] No license found](scan-setting/enable-supported-barcode-format.html) \ No newline at end of file diff --git a/license/troubleshooting-unauthorized-device-clone-detected.md b/license/troubleshooting-unauthorized-device-clone-detected.md new file mode 100644 index 0000000..e0596a2 --- /dev/null +++ b/license/troubleshooting-unauthorized-device-clone-detected.md @@ -0,0 +1,57 @@ +--- +layout: default-layout +title: Error -20151 Unauthorized Device Clone Detected +keywords: Dynamsoft Barcode Reader, Error -20151, Unauthorized Device Clone, License Error, DBR FAQ, License Validation +description: Understand the cause of error -20151 Unauthorized Device Clone Detected in Dynamsoft Barcode Reader and how to resolve it. +needAutoGenerateSidebar: false +--- + +# 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. + From db5d14a0a4f76f33370673470b0ac1caadbdea66 Mon Sep 17 00:00:00 2001 From: yqz562 <158135022+yqz562@users.noreply.github.com> Date: Wed, 4 Feb 2026 14:11:50 +0800 Subject: [PATCH 2/4] docs: Add new troubleshooting entry for unauthorized device clone and correct existing link path in license FAQ. --- license/index.md | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/license/index.md b/license/index.md index db0a24b..d4ddeca 100644 --- a/license/index.md +++ b/license/index.md @@ -20,4 +20,5 @@ Please use the links below to find answers to common questions and configuration - [How to track license usage?](track-license.html) - [New license required for per-device licensing?](new-license-required-per-device-licensing.html) - [How to get a free trial?](dbr-free-trial.html) -- [Troubleshooting - Error: [xxx] No license found](scan-setting/enable-supported-barcode-format.html) \ No newline at end of file +- [Troubleshooting - Error: [xxx] No license found](enable-supported-barcode-format.html) +- [Troubleshooting - Error: -20151 Unauthorized Device Clone Detected](troubleshooting-unauthorized-device-clone-detected.html) \ No newline at end of file From e31fa0fe7f41796bb032aa2a592daa89a2a8c5fb Mon Sep 17 00:00:00 2001 From: yqz562 <158135022+yqz562@users.noreply.github.com> Date: Wed, 4 Feb 2026 14:22:24 +0800 Subject: [PATCH 3/4] docs: Correct title format in license FAQ. --- license/enable-supported-barcode-format.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/license/enable-supported-barcode-format.md b/license/enable-supported-barcode-format.md index bb2d419..34bb7ef 100644 --- a/license/enable-supported-barcode-format.md +++ b/license/enable-supported-barcode-format.md @@ -1,6 +1,6 @@ --- layout: default-layout -title: Troubleshooting - Error: [xxx] No license found +title: Troubleshooting - Error [xxx] No license found keywords: Dynamsoft Barcode Reader, FAQ, JavaScript, tech basic, barcode format, no license found description: When moving from a trial license to a production license, you may encounter the error `[xxx] No license found` if your enabled barcode formats don't match the formats supported by your license? needAutoGenerateSidebar: false From cb795d0434aaa2cd706df3dc65a809c1e885e2f3 Mon Sep 17 00:00:00 2001 From: yqz562 <158135022+yqz562@users.noreply.github.com> Date: Wed, 4 Feb 2026 15:23:45 +0800 Subject: [PATCH 4/4] docs: Remove "Troubleshooting - " prefix from the license error FAQ title. --- license/enable-supported-barcode-format.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/license/enable-supported-barcode-format.md b/license/enable-supported-barcode-format.md index 34bb7ef..772794d 100644 --- a/license/enable-supported-barcode-format.md +++ b/license/enable-supported-barcode-format.md @@ -1,6 +1,6 @@ --- layout: default-layout -title: Troubleshooting - Error [xxx] No license found +title: Error [xxx] No license found keywords: Dynamsoft Barcode Reader, FAQ, JavaScript, tech basic, barcode format, no license found description: When moving from a trial license to a production license, you may encounter the error `[xxx] No license found` if your enabled barcode formats don't match the formats supported by your license? needAutoGenerateSidebar: false