Why I have WMI Class but no instance? - wmi

Question

I am following Microsoft guide
on how to setup my own WMI provider.
After registering my provider with Register-CimProvider.exe I can see the class:
Get-CimClass -Namespace root/StandardCimv2/sample -ClassName MSFT_WindowsProcess
NameSpace: ROOT/StandardCimv2/sample
CimClassName CimClassMethods CimClassProperties
------------ --------------- ------------------
MSFT_WindowsProcess {RequestStateChan... {Caption, Description, ElementName, InstanceID...}
However, there is no instance of this class as the next command fails:
Get-CimInstance -ClassName MSFT_WindowsProcess -Namespace root/StandardCimv2/sample
Get-CimInstance : Provider load failure
At line:1 char:1
+ Get-CimInstance -ClassName MSFT_WindowsProcess -Namespace root/Standa ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (root/StandardCi..._WindowsProcess:String) [Get-CimInstance], CimException
+ FullyQualifiedErrorId : HRESULT 0x80041013,Microsoft.Management.Infrastructure.CimCmdlets.GetCimInstanceCommand
This is my mof:
#pragma include ("cim_schema_2.26.0.mof")
#pragma include ("MSFT_Qualifiers.mof")
// MSFT_WindowsProcess class derives from CIM_Process class,
// which defines the schema for the processes running on windows OS.
[ClassVersion("1.0.0")]
class MSFT_WindowsProcess : CIM_Process
{
string CommandLine;
[Description("This instance method demonstrates modifying the "
"priority of a given process."
"The method returns an integer value of 0 if the "
"operation was successfully completed,"
"and any other number to indicate an win32 error code.")]
uint32 SetPriority([In] uint32 Priority);
[static,
Description("This static method demonstrates creating a process "
"by supplying commandline to start a new process."
"It will output the reference to the newly created process."
"The method returns an integer value of 0 if the process "
"was successfully created, and any other number to "
"indicate an win32 error code.")]
uint32 Create([In] string CommandLine, [Out] CIM_Process ref Process);
};
I followed every other step in the guide.
What I need to do to create an instance of the class?