Mongod custom activity issue

i build a csharp custom activity for mongod and import in UiPath studio but when i tried to run i got error

ERROR Validation Error Cannot create unknown type ‘{clr-namespace:OZ.Transcript.MongoConnector.Activities;assembly=OZ.Transcript.MongoConnector.Activities}PolicyHolderExists’. database.xaml

can someone help me to fix the issue

@imumeriqbal

As per error looks like it is unable to intialize the variable type you need

Is the custom activity tested?

And all the reuqired dependencies are added?

Cheers