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Last Updated: 27 Oct 2025 06:22 by ADMIN
Greg
Created on: 14 Oct 2025 07:20
Category: PdfProcessing
Type: Bug Report
3
PdfProcessing: Merging a document with RadioButtonFields throws ArgumentException: 'An item with the same key has already been added.

System.ArgumentException: 'An item with the same key has already been added. Key: Telerik.Windows.Documents.Fixed.Model.InteractiveForms.RadioButtonField'

It is reproducible when you have at least 2 pages with RadioButtonFields. The import operation goes smoothly. However, merging or removing a page after import leads to the described error.

4 comments
ADMIN
Dess | Tech Support Engineer, Principal
Posted on: 27 Oct 2025 06:22

Hi, Greg,

Тhank you for sharing the sample document with CheckBox Fields. Based on your description and the provided document, I can confirm that the error you are encountering (“An item with the same key has already been added”) is due to how RadPdfProcessing handles AcroForm fields. When merging or removing pages, fields like CheckBoxField or RadioButtonField with identical names across multiple pages cause key duplication in the internal field collection.

I would like to note that we are currently working on a solution and a fix candidate is already approved by our quality assurance workflow. It will be introduced in the upcoming release scheduled for the middle of November. Make sure that you click the Follow button to get notified for any status changes.

Regards,
Dess | Tech Support Engineer, Principal
Progress Telerik

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Greg
Posted on: 24 Oct 2025 15:18

Hello Yoan,

I have attached a document that is having the checkbox issue.

Thank you for your help !

Greg N.

Attached Files:
ADMIN
Yoan
Posted on: 24 Oct 2025 14:25

Hello Greg, 

Thank you for the additional feedback. Having as much context and as many use cases as possible would be very helpful for the development of this task. If you don’t mind, could you please share the multi-page PDF with checkboxes that you mentioned? This would allow us to review it and take it into consideration as well.

NOTE: Please note that this is a public thread, so attaching any confidential data is not recommended. If you prefer, you can open a separate support ticket and provide the document there.

Thank you in advance for your cooperation.

Regards,
Yoan
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Greg
Posted on: 23 Oct 2025 19:02
This error also appears when merging a multi-page pdf with Check-Boxes.
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