What is the meaning of this Invalid Schema error?

The schema seems to get created despite this error.

And these errors as well

And for completion here is the resulting Vendor schema

    {
  "title": "Vendor",
  "bsonType": "object",
  "required": [
    "_id",
    "_partitionKey",
    "tstamp",
    "isDeleted",
    "code",
    "name",
    "labelName",
    "details",
    "filter"
  ],
  "properties": {
    "_id": {
      "bsonType": "string"
    },
    "_partitionKey": {
      "bsonType": "string"
    },
    "tstamp": {
      "bsonType": "date"
    },
    "isDeleted": {
      "bsonType": "bool"
    },
    "code": {
      "bsonType": "string"
    },
    "name": {
      "bsonType": "string"
    },
    "labelName": {
      "bsonType": "string"
    },
    "details": {
      "bsonType": "string"
    },
    "filter": {
      "bsonType": "string"
    },
    "brands": {
      "bsonType": "array",
      "items": {
        "bsonType": "string"
      }
    },
    "products": {
      "bsonType": "array",
      "items": {
        "bsonType": "string"
      }
    }
  }
}

Here is another one