I report, I got the exact same error and I don’t know how to resolve yet…
My understanding the error is because:
It seems the grade service is trying to get the grade of an anonymous user and it then throw an exception bceause the id is not int
Now given that, should the grade fail silently or should the grade service not be called when the user is anonymous (i.e. grade shuold ignore signal when user is none)? may be there is third option…