Kickstart - Custom field | Text Area

Has anyone successfully done a Kickstart with custom form data where the custom field was a 'Text area' field or a 'Text Field with Formatting'? I'm trying to do a Task object Kickstart where a custom form is attached and a string of text (sometimes a sentence, sometimes a URL) is added to that custom field/form. Each time I import I Get this error: "The following parameter value is invalid 'Existing page URL'. Please adjust and try again." 

I've double checked that the CategoryID of the form and the Custom Field name are correct; in this instance I'm using "DE:Existing page URL". If I swap the text custom field out with a drop down custom field it works fine. Also, if I put a pipe (|) from the data delimiter tab in front of each row entry the import works but none of the custom data comes through. Any insight?