Microsoft warned customers last week that they may experience application crashes on some Windows Server 2025 due to recent memory management changes.
This known issue affects apps that use Address Windowing Extensions (AWE), a set of extensions that lets an application use more than 4GB of physical memory within a 32-bit virtual address space.
"Applications running on Windows Server 2025 might experience access violations, memory corruption, or unexpected termination," Microsoft said in a service alert first spotted by Microsoft MVP Susan Bradley.
"This issue is caused by a Windows Server 2025 memory-management change that can affect certain applications using Address Windowing Extensions (AWE) that rely on memory-management behaviors present in earlier Windows Server releases."
The list of affected applications includes SQL Server when running with the Lock Pages in Memory (LPIM) Windows policy enabled to boost performance in scenarios where paging memory to disk is expected.
On impacted systems, users may see memory corruption errors, access violation exceptions (with 0xC0000005 error codes), failures during database maintenance operations (e.g., DBCC CHECKDB), SQL Server crash dumps, and SQL Server services stopping or restarting unexpectedly.
Affected users are also seeing "Using locked pages in the memory manager." alerts in the error log during system startup.
Workaround available
While a permanent fix isn't available yet, Microsoft shared a temporary workaround that requires admins to disable the LPIM policy for the SQL Server service account.
"Customers should evaluate this workaround in their environment, as disabling LPIM can affect SQL Server performance and memory-management behavior. [..] For other applications encountering this issue, check to see if AWE can be disabled," Microsoft added.
"We are working on a resolution for this issue in a future Windows update and will provide more information when it is available."
In April, Microsoft also released emergency updates to fix a known issue causing the KB5082063 security update to fail to install on some Windows Server 2025 systems.
More recently, in June, it fixed a bug causing some Windows Server 2025 devices to boot into BitLocker recovery after installing the April 2026 security update.
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