Event ID - 521

Event Id521
SourceMicrosoft-Windows-TBS
DescriptionThe RPC subsystem could not be initialized. The error returned was %1.
Event InformationAccording to Microsoft :
Cause :
This event is logged when the RPC subsystem could not be initialized.
Resolution :
Retry the operation or restart the computer
In order to successfully use services provided by the Trusted Platform Module, applications (including components of Windows, such as BitLocker) communicate with the TPM by using TPM Base Services (TBS) and an application programming interface (API), and must receive the expected results.
To resolve this condition, try each of the following steps, as required:
Retry the particular operation.
If the application does not provide a way to retry a particular operation, close the application, and then re-open it.
Restart the computer.
If this error condition continues and none of the above steps resolves the issue, try each of the following steps, as required:
Ensure that the TPM hardware is functioning correctly.
Verify that the application is compatible with this version of Windows.
Verify that the application is compatible with the version of the TPM that is installed.
In these cases, contact your hardware manufacturer, software publisher, or support team, as appropriate.
Verify :
To perform this procedure, you must have membership in Users, or you must have been delegated the appropriate authority.
To verify the correct operation of TBS:
Restart the computer.
Verify that all applications and components that use the TPM, such as BitLocker Drive Encryption, work correctly without errors appearing on screen or in the Event log. Specifically, the following steps can verify the correct operation of BitLocker:
Verify that Windows Welcome Screen, Logon Screen or Desktop appears. This indicates that BitLocker has correctly unlocked the Windows operating system volume.
Log on to Windows and access any data volumes that are encrypted with BitLocker.
Note: Data volumes can be configured to be automatically unlocked or to require manual unlocking.
Reference LinksEvent ID 521 from Microsoft-Windows-TBS

Catch threats immediately

We work side-by-side with you to rapidly detect cyberthreats
and thwart attacks before they cause damage.

See what we caught

Did this information help you to resolve the problem?

Yes: My problem was resolved.
No: The information was not helpful / Partially helpful.