Microsoft removed a compatibility hold after fixing a known issue that would lead to Qualcomm Bluetooth radios having issues discovering and connecting to Bluetooth devices because of outdated drivers after installing or updating to Windows 10 1903.
Redmond applied the update block on May 21 to prevent devices featuring affected driver versions for Qualcomm Bluetooth radios from being allowed to install the Windows 10, version 1903 or Windows Server, version 1903 updates until the driver has been updated.
The Qualcomm Bluetooth discovery and connectivity issue has been resolved with the release of the KB4517389 cumulative update.
While the safeguard hold has been removed, customers should know that "it can take up to 48 hours before you can update to offered Windows 10, version 1903 or Windows Server, version 1903."
Devices with Realtek Bluetooth radios still blocked
The original issue acknowledged by Microsoft in May also affected devices with Realtek Bluetooth radios and, unfortunately, that issue has not yet been resolved.
Because of this, the issue's entry has been split in two, with the Realtek one still being listed on the list of known issues and notifications available on the Windows 10 Release Information Dashboard.
However, Microsoft provides a workaround for affected customers, advising them to check with their "device manufacturer (OEM) to see if an updated driver is available and install it. You will need to install a Realtek driver version greater than 1.5.1011.0.users."
Redmond also recommends impacted users to not apply the Windows 10 May 2019 Update "using the Update now button or the Media Creation Tool" before updating their system's Bluetooth drivers or before the update is being automatically provided through the Windows Update system.
Right now there are five update blocks on preventing some devices to upgrade to Windows 1903, version 1903 (mitigation measures are available for three of the known issues behind them):
• Unable to discover or connect to Bluetooth devices (Mitigated)
• Intel Audio displays an intcdaud.sys notification (Mitigated)
• Cannot launch Camera app (Mitigated)
• Safeguard on certain devices with some Intel and Broadcom Wi-Fi adapters (Resolved)
• AMD RAID driver incompatibility (on for older AMD RAID drivers)
Previous Windows 10 1903 Bluetooth issues
The May issue that impacted computers with Realtek or Qualcomm Bluetooth radios and leading to connectivity and discovery issues was not the first that led to Windows 10 1903 Bluetooth problems.
One month later, in June, users again started encountering Bluetooth pairing and connectivity issues after installing recently released cumulative, security, or monthly rollup updates because of Redmond blocking some Bluetooth devices due to security risks.
"These security updates address a security vulnerability by intentionally preventing connections from Windows to unsecure Bluetooth devices," said Microsoft at the time. "Any device using well-known keys to encrypt connections may be affected, including certain security fobs."
In August, Microsoft said that Bluetooth speakers will stop connecting to devices running Windows 10, version 1903 after installing the KB4505903 cumulative update issued on July 26, 2019.
Besides the Bluetooth speakers no longer working correctly, a yellow exclamation mark icon was also displayed on the Microsoft Bluetooth A2dp Source entry under the Sound, video and game controllers node in Device Manager.