Notice: Undefined index: content_attributes in Drupal\socialbase\Plugin\Preprocess\Page

Problem/Motivation

hi
i am try to build a custom reference selection with the https://www.drupal.org/project/entity_browser → Module.

After creating the view's reference display (entity browser), when on node, trying to reference other content through the provided modal window by entity browser, i got the error that you can see in attach file.
Using another vanilla d8 install doesn't throw that Notice error.

Can somebody help please ?
Thanks