icacls C:\Windows\System32\synsoacc.dll /reset Temporarily uninstall any non-Microsoft antivirus or EDR software. Reboot into Safe Mode with Networking . If the error disappears in Safe Mode, the culprit is a third-party filter driver or security hook. Reinstall the security software but add an exclusion for C:\Windows\System32\synsoacc.dll and lsass.exe .
DISM /Online /Cleanup-Image /RestoreHealth After DISM completes, reboot and run SFC again.
In the sprawling ecosystem of the Windows operating system, few error messages are as cryptic—and as frustrating—as the one referencing synsoacc.dll and a “protected object server.” For the average user, this pop-up can appear during seemingly mundane tasks: logging into a domain-joined machine, attempting to change a password, accessing a shared network resource, or even just unlocking a workstation after a coffee break. The message, often accompanied by an Event ID in the System Log, is not merely a random glitch; it is a signal that a core component of Windows Security and authentication has encountered a critical inconsistency.
Run the following from an admin command prompt:
sfc /scannow This will replace any corrupted versions of synsoacc.dll from the cached WinSxS folder. If SFC reports corruption but cannot fix it, proceed to:
Run the System File Checker from an elevated command prompt:
icacls C:\Windows\System32\synsoacc.dll /reset Temporarily uninstall any non-Microsoft antivirus or EDR software. Reboot into Safe Mode with Networking . If the error disappears in Safe Mode, the culprit is a third-party filter driver or security hook. Reinstall the security software but add an exclusion for C:\Windows\System32\synsoacc.dll and lsass.exe .
DISM /Online /Cleanup-Image /RestoreHealth After DISM completes, reboot and run SFC again. icacls C:\Windows\System32\synsoacc
In the sprawling ecosystem of the Windows operating system, few error messages are as cryptic—and as frustrating—as the one referencing synsoacc.dll and a “protected object server.” For the average user, this pop-up can appear during seemingly mundane tasks: logging into a domain-joined machine, attempting to change a password, accessing a shared network resource, or even just unlocking a workstation after a coffee break. The message, often accompanied by an Event ID in the System Log, is not merely a random glitch; it is a signal that a core component of Windows Security and authentication has encountered a critical inconsistency. Reinstall the security software but add an exclusion
Run the following from an admin command prompt: The message, often accompanied by an Event ID
sfc /scannow This will replace any corrupted versions of synsoacc.dll from the cached WinSxS folder. If SFC reports corruption but cannot fix it, proceed to:
Run the System File Checker from an elevated command prompt: