This last error is related to having a Type with an unknown predicate. So you have to check the list of predicates in the Type and set the missing one in the schema. e.g:
type VM {
Pred1
PredB
missing_one
}
Pred1: string @index(exact) .
PredB: [uid] .
missing_one: string @index(term) . #This one is the missing one that exists only in the type.
Do you still have the interface is nil error?