Doctrine ODM association not loaded - php

Question

I've started working with Doctrine MongoDB ODM. I have a Document called Document which has an association originalFile to another document called File.
class Document extends AbstractDocument
{
/**
* #var integer $id
*
* #MongoDB\Id
*/
protected $id;
/**
* #var ImportSource
*
* #MongoDB\ReferenceOne(targetDocument="ImportSource", cascade="all", simple=true)
*/
protected $importSource;
/**
* #var DocumentState
*
* #MongoDB\ReferenceOne(targetDocument="DocumentState", cascade="all", simple=true)
*/
protected $state;
/**
* #var \DateTime $created
*
* #MongoDB\Date
*/
protected $created;
/**
* #var \DateTime $modified
*
* #MongoDB\Date
*/
protected $modified;
/**
* #var File $formattedFile
*
* #MongoDB\ReferenceOne(targetDocument="File", cascade="all")
*/
protected $formattedFile;
/**
* #var File $originalFilename
*
* #MongoDB\ReferenceOne(targetDocument="File", cascade="all")
*/
protected $originalFile;
//getters, setters etc..
}
File:
class File
{
/**
* #var string
*
* #MongoDB\Id
*/
protected $id;
/**
* #var FileType
*
* #MongoDB\ReferenceOne(targetDocument="FileType", cascade="all", simple=true)
*/
protected $type;
/**
* #var string
*
* #MongoDB\String
*/
protected $basename;
/**
* #var \DateTime
*
* #MongoDB\Date
*/
protected $created;
/**
* #var \DateTime
*
* #MongoDB\Date
*/
protected $deleted;
/**
* #var \MongoGridFSFile
*
* #MongoDB\File
*/
protected $file;
Storing the Document works without any problems. The Document and the File-Document are stored in MongoDB. When I'm loading the Document the $originalFile property is null. I have no clue what's missing. Is the mapping wrong or is this simply a bug in Doctrine?
Edit:
This is how I'm storing the documents:
//create if not exists
if ($documentObj === null) {
$documentObj = new Document();
$documentObj->setCreated(new \DateTime());
//create file
$file = new File();
} else {
$documentObj->setModified(new \DateTime());
//get file
$file = $documentObj->getOriginalFile();
}
$file->setFile($pathToFile);
//set file
$documentObj->setOriginalFile($file);
//set import source
$documentObj->setImportSource($source);
//store document
$documents[] = $this->storeDocument($documentObj, $documentFields);
//... method storeDocument fills other properties of the document and finally persits the document:
$this->manager->persist($documentObj);
$this->manager->flush();

Answer 1

I have no clue why, but it's working now... I was occupied with other projects for a few days, returned to this projects, ran my unit tests again and everything worked. Only thing I've done was a composer update. Maybe a bug correlating with my setup.

Answer 2

I got such problem, it is related to metadata cache, just run
bin/console cache:clear
bin/console doctrine:cache:clear-metadata
Also good to know these commands, if you are using symfony built-in cache
bin/console doctrine:cache:clear-query
bin/console doctrine:cache:clear-result