When you have an SSD System disk, you will get the following error logged in your Event Log:
The volume System Reserved was not optimised because an error was encountered: The parameter is incorrect. (0x80070057)
Source: Microsoft-Windows-Defrag
Event ID: 257
This is because Windows 8 and above does not optimise or defrag SSD disks. This is because SSD disks only have so many writes per block and defragging / optimising unnecessarily uses these writes.
Really, the volume System Reserved was not optimised error should be removed from the event log if the system disk is an SSD, because it’s just not relevant. Microsoft are yet to do this 🙁