In the world of mobile repair and firmware flashing, the "Handshaking... Error Unexpected Response 0x68" is a common hurdle, often seen when using tools like UnlockTool to bypass FRP or flash Android devices. The Troubleshooting Story Imagine you're trying to flash a device. You've connected everything, but the software hangs at "Handshaking" and throws error . Here is how to resolve it: Check the "Handshake" Cable The "handshake" is the initial communication between your PC and the phone's BootROM. Error 0x68 often means the signal is weak or interrupted. Use a high-quality, original USB cable and avoid using front-panel USB ports on desktop computers—plug directly into the motherboard ports at the back. Driver Conflicts If your PC "sees" the device but doesn't understand its response, it’s likely a driver issue. Ensure you have the latest MTK/SPD drivers installed. Many users find success by using a "Filter" in LibUSB-win32 to specifically capture the device's connection during the handshake phase. Force the Connection (The Key Combo) Handshaking often fails if the device isn't in the correct mode (like BROM mode for MTK chips). Volume Up + Volume Down while plugging in the USB cable. This "forces" the handshake to happen on the correct port. Software Environment Sometimes, antivirus software or other phone managers (like iTunes or Samsung Smart Switch) interfere with the serial port communication. Disable these temporarily to give your flashing tool exclusive access to the USB port. If you’d like more specific help, let me know: are you using (e.g., UnlockTool, SP Flash Tool)? What is the of the phone? were you trying to perform (e.g., Factory Reset, FRP Bypass, Flashing)? I can give you the exact "button combo" or driver link for your specific device. How To Fix Unlocktool Handshaking Failed Error Fix 17 Jun 2025 —
The error message "handshaking... error unexpected response 0x68" typically occurs when a software tool, such as UnlockTool , fails to establish a secure connection with a device's hardware (often a mobile phone) during a flashing or unlocking process Common Causes Driver Issues: Incorrect, outdated, or conflicting USB drivers (especially MediaTek/MTK or LibUSB drivers) often cause communication failures. USB Connection: A faulty cable, a loose port, or using a USB 3.0/3.1 port (which can sometimes be incompatible with older flashing tools) can trigger this error. Hardware State: The device may not be in the correct mode (e.g., BROM mode or EDL mode) required for the handshake to complete. Server Interruption: Some tools require an active connection to their own authentication servers; a network timeout can result in an "unexpected response." Wöhler Technik GmbH Recommended Fixes Reinstall Drivers: Completely uninstall existing USB drivers and reinstall the specific MTK or LibUSB drivers recommended for your tool. Change Ports/Cables: Use a high-quality original data cable and try a USB 2.0 port instead of a blue USB 3.0 port. Check Device Mode: Ensure the device is powered off and you are using the correct button combination (usually Volume Up + Volume Down) when connecting to enter the necessary mode. Disable Antivirus: Security software can sometimes block the low-level communication required for handshaking. Temporarily disable your firewall or antivirus and run the tool as an Administrator. Are you using a specific software like UnlockTool SP Flash Tool when this error appears? Fix SP Flash Tool COM Port Open Error: A Simple Guide - Crawler
The error "Handshaking... Error Unexpected Response 0x68" is a specific communication failure typically seen when using certain firmware flashing tools (like Miracle Box , SP Flash Tool , or Infinity-Box ) to interact with mobile devices . The hex code 0x68 generally indicates that the device's bootloader or security processor returned a signal that the software did not expect during the initial "handshake" phase. Common Causes Secure Boot / Authentication : Many modern devices have a "Secure Boot" enabled. If you try to flash or read the device without a specific "DA" (Download Agent) file or an authentication file ( .auth ), the device rejects the connection with this error. Driver Mismatch : The computer may be using an incorrect or outdated VCOM/Preloader driver, causing the data packets to be misinterpreted. Hardware Connection : A loose USB cable, a damaged charging port, or insufficient power (low battery) can cause the handshake to drop midway. Incorrect CPU Selection : If you have selected the wrong chipset (e.g., selecting MT6580 when the device is MT6735) in your service tool, the boot sequence will fail. Troubleshooting Steps Use a Custom DA File : In your flashing software, manually select a "Download Agent" (DA) file specifically designed for your device model rather than the default one. Disable Driver Signature Enforcement : If you are on Windows 10 or 11, you may need to disable digital driver signing to allow the VCOM drivers to function properly. Check Connection Mode : Try connecting the device while holding Volume Up , Volume Down , or both buttons simultaneously before plugging in the USB. Try a different USB port (preferably a USB 2.0 port on the back of a PC). Verify Battery Level : Ensure the device has at least 30-50% charge; a low battery can cause the processor to "brown out" during the high-power handshake phase. Use an Auth Bypass Tool : If the device has a MediaTek (MTK) processor, you might need a "Bypass" utility to disable the bootroom protection before the flashing tool can establish a handshake.
The error "handshaking... error unexpected response 0x68" is most commonly encountered when using Unlock Tool or similar software to service mobile devices (often Oppo or MediaTek-based phones). It typically signifies a protocol mismatch or a failure in the initial communication between the software and the device's bootloader . Primary Cause & Solution This specific error is usually caused by missing or incorrect USB drivers , specifically the libusb-win32 or MTK drivers, which prevent the tool from correctly "handshaking" with the device in its pre-loader or brom mode. Standard Troubleshooting Steps: Install LibUSB Drivers: Ensure you have the libusb-win32 drivers installed. Many tools require you to use the "Filter Wizard" within LibUSB to select the device while it is connected in its specific boot mode. Check USB Connection: Use a high-quality data cable and try different USB ports (preferably USB 2.0 if available, as USB 3.0/3.1 can sometimes cause timing issues with these tools). Disable Driver Signature Enforcement: On Windows, you may need to disable driver signature enforcement to allow the specialized mobile drivers to function correctly. Device State: Ensure the device is in the correct mode (e.g., holding Volume Up + Volume Down while plugging in the cable) as required by the specific tool. Other Contexts While less common, similar "unexpected packet format" or handshake errors can occur in other network-based environments: IMAP/Email Migration: In tools like MigrationWiz , this error often means you are attempting an SSL connection on a port that only supports non-SSL (or vice versa). SSH/Terminal: If seen in a terminal, it might indicate a mismatch in supported ciphers between your client and the server, which can sometimes be fixed by updating your SSH configuration to allow older or specific encryption types. Are you using a specific mobile unlocking tool when this error appears? The handshake failed due to an unexpected packet format handshaking... error unexpected response 0x68
This error indicates a protocol mismatch or baud rate disagreement during the serial handshake. The 0x68 response is often a "NACK" (Negative Acknowledge) or a status byte in protocols like IEC 60870-5-101/104 , DLMS/COSEM , or custom embedded systems . Here is a solid troubleshooting guide for Handshaking... error unexpected response 0x68 .
1. Identify Your Protocol 0x68 has common meanings:
IEC 60870-5-101/104 : 0x68 is the start byte of a frame (not an error response). Receiving it unexpectedly means the device is sending data out of sync. DLMS/COSEM : 0xE6 is typical for handshake; 0x68 might be a baud rate detection echo. Modbus RTU : Invalid response (should be device address or function code). Raw serial : Possibly 'h' (ASCII 0x68 = letter 'h'). In the world of mobile repair and firmware
2. Immediate Checks | Check | Action | |-------|--------| | Baud rate | Ensure matching rates (e.g., 9600, 19200, 57600). Try auto-baud detection if supported. | | Data bits | Usually 8. | | Parity | Even, Odd, or None – must match device config. | | Stop bits | 1 or 2. | | Flow control | Disable hardware handshake (RTS/CTS) unless explicitly required. | 3. Common Fixes by Scenario Scenario A: IEC 60870-5-101 (serial RTU)
Cause : Device sends 0x68 (start of frame) but your master expects a different handshake response. Fix :
Send correct STARTDT (start data transfer) command: 0x68 0x04 0x07 0x00 0x00 0x00 0x52 Expect 0x68 0x04 0x07 0x00 0x00 0x00 0x0B as ACK. You've connected everything, but the software hangs at
Scenario B: DLMS/COSEM (smart meters)
Cause : Baud rate detection phase – meter echoes 0x68 after receiving a sign-on character (often 0x00 or 0xFF ). Fix :
