netbox.exceptions.ClientException: Invalid value for custom field 'VLAN_Domain_ID': Value must be a string.

[harryjr]

I am having trouble importing the custom fields yaml file. I get:

<class 'AttributeError'>

'NoneType' object has no attribute 'app_label'

Python version: 3.9.13
NetBox version: 3.4.5

I have tried to create them manually but am receiving this error when the script is creating the vlan group:

	print("Creating VLAN Groups")
	cursor.execute("SELECT id,description FROM VLANDomain")
	vlans_domains = cursor.fetchall()
	for Id, description in vlans_domains:

		vlan_domain_id_names[Id] = description

		if description not in existing_vlan_groups:
			netbox.ipam.create_vlan_group(name=description, slug=slugify(description), custom_fields= {"VLAN_Domain_ID":Id}) <-- line of error

Here is the data it is collecting from racktables:

mysql> SELECT id,description FROM VLANDomain\G
*************************** 1. row ***************************
id: 5
description: Company name
*************************** 2. row ***************************
id: 7
description: Company name - DR Isolated Network