At a total loss as to what is the cause of this error. The field was added to a Message Notify template entity. It is basically used as a token in emails sent using that module. The only place in my custom code that i use this field is to set its value from a value collected in a modal form. When submitting the modal; this error occurs.
The crazy part of this is that i have removed the field from the entity (so no longer exists in visible config in the site). I have also commented out the 1 line of code that refers to this field. After a db search the only tables to reference this field are config_snapshot and config_import. There were entries there for the field which i removed and the only records which remain are for the bundles which used to hold this field. Can’t find any reference to what these tables are for but guessing they are only records of past import and not actively used.
To add to the crazy, this all works fine on my local dev copy of the site.
I have run cron and cr numerous times.