Drupal 8.x

I'm having the following problem: every page from my website gets an error. In google chrome:

Uncaught TypeError: Cannot set property 'innerHTML' of null
    at HTMLDocument.<anonymous> (<anonymous>:1:273)
    at j (jquery.min.js?v=3.2.1:2)
    at k (jquery.min.js?v=3.2.1:2)
    at g (<anonymous>:34:370)

in firefox:

TypeError: document.getElementById(...) is null

Hi, I created a custom entity with these fields: id, uuid, name, user_id.
I try to print the value of user_id in admin but without results.
$entity->get('user_id')->value
$entity->get('user_id')->getValue()
$entity->user_id->value

Nothing, I can't access the value, while for the other fields I have no problem.

Do you have solutions?

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