Adding custom field to Service Desk customer portal

[Kristoffer Bundgaard]

I can't add my custom field CWP to the customer portal. I get the following error:

My custom field type is "Database Values Selection Field". I have added it to all relevant screens. 

[Nic Brough -Adaptavist-]

The Service Desk can only expose fields that have been coded to support it (this is a two-way thing, the custom field needs to support Service Desk, and Service Desk needs to support the field)

Database fields are missing one or both sides of this support, because they're too different to the standard Atlassian custom fields.  I suspect it's both sides that can't support them.