Resolved The article ID is not a number. Received value:

Subject: Subform custom field import saves wrong JSON format (row0 wrapper)

Hi,

I'm using RO CSVI 9.5.3 with Joomla 6.0.4 on PHP 8.4 to import Joomla content articles with a Subform custom field.

## Setup

- Joomla 6.0.4
- RO CSVI 9.5.3
- PHP 8.4.16
- Custom field "glossar" (ID 32), type: Subform
- Subform contains two fields: "title" (text, ID 2) and "textarea" (textarea, ID 10)
- Field is NOT set to repeatable

## CSV import file

"title";"catid";"state";"glossar"
"API";"8";"1";"title#A|textarea#This is a test text."

## Problem

RO CSVI recognizes the field correctly as Subform type in Available Fields. However, when importing, it saves the value in the database (fields_values table) in the Repeatable/multiple-row format:

{"row0":{"field2":"A","field10":"This is a test text."}}

The correct format for a non-repeatable Subform field in Joomla 6 is:

{"field2":"A","field10":"This is a test text."}

The row0 wrapper causes Joomla to not display the Subform field values correctly in the frontend.

## Additional note on version 9.6.1

With RO CSVI 9.6.1 the same import template produces the error: "The article ID is not a number. Received value:" — the import works fine with 9.5.3.

## Expected behavior

When importing a non-repeatable Subform custom field, RO CSVI should save the JSON value without the row0 wrapper, matching how Joomla itself stores the data.

Thank you for looking into this.

Best regards