Bluetooth LE device stopped connecting in Windows 10 v1709 RRS feed

  • Question

  • I've created a WDK library for interacting with a Bluetooth LE device. The library worked well - I was able to connect to my device, write characteristics and get asynchronous notifications. Once I updated to Windows to version 1709 (build 16299.98), the library stopped working:

    1. pair the device via Settings-->Devices-->Bluetooth
    2. the BLE device blinks a led as an indication of Advertising
    3. Run my application
    4. Once the application opens the BLE device's handle (using hDevice = CreateFile(pInterfaceDetailData->DevicePath, GENERIC_WRITE | GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);), the device blinks spasmodically, indicating that it connects and disconnects very fast.
    5. Sometimes, after several long seconds, the device has solid light, indicating it is connected (the status in Windows Settings is also 'Connected')
    6. Any access to the device from my code (e.g. calling BluetoothGATTSetDescriptorValue() to enable BLE notification), fails with a timeout

    For some reason, first-time pairing with the device does not exhibit these symptoms. 

    Any ideas?


    If its relevant, my local Bluetooth device is Qualcom Atheros USB module  (VID_0489&PID_E076&REV_0001).

    • Edited by bavaza Tuesday, December 12, 2017 4:46 PM
    Tuesday, December 12, 2017 10:58 AM

All replies

  • Hi,

    having a similar issue with the C# side. Im always initializing all services/characteristics one after another. The first 1-2 services get initialized well (most time GATT & GACC) then some custom services should get initialized an the async function


    throws an exception (System.IO.FileLoadException) telling a file is locked by another process.

    For me this happens if I pair a device and then restart the PC. Before restarting all is fine. After restart the problem above occurs.

    If I depair & repair the device - it works again - till next restart. Maybe it's the same for you?

    Not sure if it's related - but it's a serious issue for me - AGAIN our customer devices are down - and i don't have a solution yet.

    I figured this out some time ago - and already submittet a an issue by feedback hub - sadly no feedback from microsoft yet and problem seems to get worse...


    BTW: Are you sure that its 1706? For me build 16299.98 is 1709.

    • Edited by f_pabst Tuesday, December 12, 2017 12:30 PM
    Tuesday, December 12, 2017 12:29 PM
  • Oops, you are correct: Windows 10 Pro, Version 1709, OS Build 16299.98 - I'll fix the question.

    Also, as with you, if I unpair and pair again - I'm able to work as before.

    Tuesday, December 12, 2017 4:28 PM
  • Thanks for reaching out to us. The Bluetooth team would like some more information to be able to diagnose the problem. Please capture Bluetooth traces to help us investigate.

    To capture traces, please follow these instructions:

    • Unzip (  to your computer.
    • Open an elevated (administrator) command prompt and perform the following actions in it.
    • Run “ifr_setup_bth.cmd” to enable verbose tracing.
    • Reboot or disable/enable the Bluetooth device in Device Manager, so that the verbose tracing takes effect.
    • Run “bth_trace”, but do not press a key when prompted.
    • Toggle the Bluetooth radio off-on via the quick action menu or force a power cycle of the remote device (we need the connection information).
    • Repro the issue.
    • Press any key in the logging command prompt to capture the log file.

    Create and attach a ZIP file with the following contents:

    • C:\bth_tracing.etl
    • C:\windows\inf\setupapi.*.log
    • C:\Windows\Panther\setupact.log
    • C:\windows\logs\windowsupdate\*.*
    • Any relevant screen shots.

    Additionally, please include the exact OS build number and architecture (x86 or x64) that was being tested.


    Aruna (Microsoft)

    Thursday, December 14, 2017 9:22 PM
  • Thanks Aruna.

    The trace you requested, for OS Build 16299.64 (I had to downgrade my machine after it auto-updated), can be found here.

    System info: Windows 10 Pro, 64-bit, Version 1709, Build 16299.64.



    after updating to build 16299.125, the problem was resolved.

    Looking at the KB4054517, I saw that a Bluetooth fix for non-bonding devices (like mine) was included:

    "- Addresses issue with personalized Bluetooth devices that don't support bonding."

    Can you confirm from my traces that the issue was indeed resolved in 16299.125?

    For your reference, here are traces from build 16299.125 with the issue resolved.

    • Edited by bavaza Monday, December 18, 2017 9:46 AM added resolved traces
    Sunday, December 17, 2017 7:47 AM