Good morning, once the model has been trained and saved to disk, then when trying to load it, it returns an error
Cannot convert undefined or null to object
TypeError: Cannot convert undefined or null to object\n at Function.keys ()\n at NeuralNlu.fromJSON

I am training the network with:
var FileName = "./ScriptsNodejs/ModelsTrained/ModelTrained.json";
const manager = new NlpManager({ languages: ['es'], forceNER: true, modelFileName: FileName, autoSave: false });
manager.train();
manager.save();

and then to load it (in other process):
var FileName = "./ScriptsNodejs/ModelsTrained/ModelTrained.json";
const manager = new NlpManager({ languages: ['es'] });
manager.load(FileName);

I have also tried with the import method and it returns the same error:
var FileName = "./ScriptsNodejs/ModelsTrained/ModelTrained.json";
const data = fs.readFileSync(FileName, 'utf8');
const manager = new NlpManager({ languages: ['es'] });
manager.import(data);

Can anyone know what causes this error?

Thank you very much