What does 'widget model not found' typically indicate in Escher?

The error 'widget model not found' in Escher generally means that the system cannot locate the specified widget model that's referenced in your code. This can occur if the model hasn't been properly defined, the name used to reference it is incorrect, or the model is not installed or accessible within the Escher environment. Double-check the model name and its existence in the Escher documentation or available models.