: Remove the USB drive once the main screen is visible; the error message should no longer appear. Software & Connection Fixes
If you use ZKTeco’s Visible Light technology, lighting is key.
utility to ensure the device IP and serial numbers match and that the correct communication ports (often found in the app.config file) are open. Firmware Integrity zkteco authentication failure solution best
Buggy or outdated firmware can cause internal matching algorithms to crash.
Re-add the device using its static IP address and communication key, then re-upload the user database. Phase 4: Best Practices for Long-Term Prevention : Remove the USB drive once the main
If fingerprint fails, try using an ID card or PIN. 3. Technical Solutions for "Failed" Authentication
: In the root directory of the USB drive, create a folder named DeleteLicense . Firmware Integrity Buggy or outdated firmware can cause
Choose or Delete AttLogs to wipe old attendance logs.
When a device's internal storage reaches maximum capacity for logs or user templates, it struggles to process new authentication requests efficiently. Open your ZK software platform. Navigate to .
If the machine won't boot, you may need to replace the adapter or power board. Summary Checklist "Please Try Again" Clean sensor, re-register user. Machine Locked/Frozen Hard reboot (power down for 30s). Authentication Sync Failure Check IP/Network Settings. Frequent Unknown Errors Update firmware.
For login errors within ZKTeco desktop applications (like ConDev): Installation & User Guide - ZKTeco