Christian Flothmann

Can you show the stack trace for this exception?

Does it work with Symfony 4.1 (I guess this requires symfony/symfony#23888).

Yes, the `int` part is important here. The following should work: ```php $config = [ 'document_managers' => [ 'dm1' => [ 'metadata_cache_driver' => [ 'type' => 'memcached', 'class' => 'fooClass',...

I do not know how Sonata sets up the form type at all, but having some Intl date formatter involved when talking about a date picker looks at least a...

That's probably not enough. You also need to consider a way to determine whether or not a possible result is the object currently being modified (the current implementation checks for...

Can you create a small example application that allows to reproduce your issue?

I am going to close here for now due to the lack of feedback. Please let us know when you have more information and we can consider to reopen.

Yes, please create a small application that allows to reproduce your issue.

I can reproduce the issue with the example, but I have no idea how to properly fix this.

@raveren Would you like to send a request to the [documentation repository](https://github.com/symfony/symfony-docs) to update the docs accordingly?