Warning: Trying to access array offset on value of type null in FieldInfo->prepareInstanceDisplay()

Problem/Motivation

I get the following error on pages rebuilding caches, or using this field. ...

Warning: Trying to access array offset on value of type null in FieldInfo->prepareInstanceDisplay() ;

Also when running twice: drush cc all

Trying to access array offset on value of type null field.info.class.inc:628 

Proposed resolution

Field definition has a typo definining a non existent default formatter. Patch will follow.