Microsoft released Windows 10 update KB4505903 for all those systems that are running Windows 10 version 1903 on July 26. This update introduced various issues for Windows 10 users. One of the major problems that were reported by hundreds of people was related to Bluetooth speakers.

Now Microsoft has acknowledged the issue, but the impact of this problem is still unknown. The company warned that you might experience problems while connecting to a Bluetooth speaker if your device already contains an internal speaker.

It is worth mentioning that KB4505903 is an optional update available for Windows 10 systems. It clearly means that your systems will not install the update unless you manually press the Check for updates button. The company mentioned in a support document that the installation breaks the Bluetooth functionality. Moreover, some devices might experience a noisy speaker output.

Additionally, in some cases, your system might get successful in establishing a Bluetooth connection but you might hear the sound directly from the internal speakers rather than the Bluetooth speakers. Microsoft further stated that you can open Device Manager to check the status. You will see an exclamation mark on the Microsoft Bluetooth A2dp icon Source.

Someone who experienced a similar problem reported the issue on Reddit. If you look at the general description of the Microsoft Bluetooth A2dp Source you will find the following error message:

Windows cannot verify the digital signature for the drivers required for this device. A recent hardware or software change might have installed a file that is signed incorrectly or damaged, or that might be malicious software from an unknown source. (Code 52).

Microsoft Suggests A Quick Word Around

Luckily, Microsoft has proposed a workaround to resolve this problem in the support article. You should try repairing the missing or corrupted files with the help of the System File Checker (SFC.exe) tool. Those who are affected by a similar problem should follow the steps mentioned below.

  1. Use the administrative authority to open the Command Prompt.
  2. Type the following command, and then press Enter in the Command Prompt window: sfc /scannow

Your system might take some time to complete the process. You can see the progress in the Command Prompt itself. Finally, reboot your Windows 10 system to apply the changes. The Bluetooth pair error should disappear now.

It is not the first time that Windows 10 updates have caused problems with Bluetooth connections. However, it remains to be seen when Microsoft decides to release a corresponding patch.