Custom Field is disabled I have created a D8 module for creating a custom field. I have done it following the given links.    

https://www.drupal.org/node/2052601
https://www.drupal.org/node/2620968
https://www.drupal.org/node/2620966

I have created an module.info.yml file . Then created a three folders inside

/src/Plugin/Field , namely,


FieldFormatter
FieldType
FieldWidget


I have coded in each of the folders as per the links. 
I could see my custom field in the field list. But my problem is that it is categorized under disabled. Please help me to figure out the problem.
After both your field and your field instance are created, you need to enable it in the related form:

entity_get_form_display('node', $bundle, 'default')
  -&gt;setComponent('field_custom', array(
    'type' =&gt; 'string'
  ))
  -&gt;save();