Module development and code questions

I have this problem to update a view with the views module, when making a change it shows me on the screen a chain of characters similar to a query in the database, how can I solve it

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I have the Message module on Drupal 8 and I have created a Flag to mark the Message.

The machine name of my flag is mark_message

How to display the Flag token (the link of the flag to mark and stand out) on my message?

Here is the code in message_activity_stream.tokens.inc, but it does not end :

Hello,

I am using Drupal 8. Since a few days every action that has a loading bar, for example my product import or updating or uninstalling modules all get stuck on 0% or waiting to initialize.

Also as seen on this screenshot: https://imgur.com/HqLbfpb, all the dropdowns are looking very weird.

I got a custom module called: ManageFinishDate

And the module name: managefinishdate.module

And the content type machine name I want this module to touch with: to_do_item

Just curious about something. If I pass a node to a method, is it better to use Node or NodeInterface, and what is the difference between the two when using it like this? Example. 

$node = Node::load(123);
$this->doSomethingToNode($node);

public function doSomethingToNode(NodeInterface $node) {
  ...
}

I have a site on Drupal 8 with the Message, Flag and Token modules.

I created a custom module to create a message when an entity is created on the site.

I also created a flag to mark messages as read. His machine name is mark_message

How to add a token with the flag to the Message module ?

Here is the file message_activity_stream.tokens.inc :