User command error on return value validation

[Nokitoo]

export class PlayerModule {
    async list(state: mage.core.IState) {
        const players = await Player.list(state, {});
        console.log(players);

        return players;
    }
}

The validation of the return value players makes classValidator.validate crash, and I don't know where it could come from.

I don't think it comes from my topic because I can correctly create data with it using @Acl and validation decorators.

[stelcheck]

What is the error stack? First guess would be that the backend vault for player does not support list, but maybe the error being thrown isn't clear enough.

[Nokitoo]

[MAGE state] Cannot read property 'prototype' of undefined
  error: {
    "type": "TypeError",
    "file": "MetadataStorage.ts",
    "line": 79,
    "offset": 37,
    "stack": [
      "src/metadata/MetadataStorage.ts:79:37",
      "Array.filter (<anonymous>)",
      "MetadataStorage.getTargetValidationMetadatas (src/metadata/MetadataStorage.ts:75:61)",
      "ValidationExecutor.execute (src/validation/ValidationExecutor.ts:44:54)",
      "Validator.coreValidate (src/validation/Validator.ts:31:18)",
      "Validator.validate (src/validation/Validator.ts:56:21)",
      "Object.validate (src/index.ts:49:44)",
      "validateObject (node_modules/mage-validator/src/decorators.ts:157:31)",
      "Function.value (node_modules/mage-validator/src/decorators.ts:218:16)",
      "<anonymous>"
    ]
  }
  data: {
    "description": "players.list",
    "actorId": "fff135d0-58c8-4591-9aa9-fc605155ec24"
  }

[stelcheck]

@Nokitoo can you confirm if this is still an issue?