Microsoft has officially acknowledged that the August security updates for Windows Server 2016 and 2025 contain bugs causing system instability. The issues affect both physical servers and virtual machines, including those running on VMware and Azure platforms.
On Windows Server 2016, the update causes the CompatTelRunner.exe process to crash, triggering the 0xc0000409 error. This component is responsible for compatibility telemetry, which assesses hardware and software requirements for future system updates.
For Windows Server 2025, the update introduced memory management changes that impact applications utilizing Address Windowing Extensions (AWE). This feature allows 32-bit applications to access more than 4GB of physical memory.
Affected systems may experience memory corruption, access violations, and the 0xC0000005 error code. These issues can lead to SQL Server crashes, failed database maintenance tasks, and unexpected service restarts.
Microsoft has not yet released a permanent fix for these problems. As a temporary workaround, the company suggests that administrators evaluate disabling the Lock Pages in Memory (LPIM) policy for SQL Server service accounts, noting potential performance impacts.
